I'll try not to make this too long of a post.
As someone who doesn't like to read extremely long posts myself I can sympathise with others who dislike that sort of thing.
Because I like to put things in chronological order I will start with the earliest example of the behavior that I want to describe.

Many years ago I discovered that I had good searching skills and part of that was an absolute refusal to give up whatever it was that I was searching for.
Even before the internet came along I used public libraries and all of their resources to find whatever information I was fascinated with or felt that I needed to know.
I have always been a relentless searcher with an insatiable thirst for knowledge and if I should run up on any roadblocks in my searches then, I simply wait a while and then, pick up where I left off some time later.
I never give up my searches on anything even if I loose interest for a while. I always come back to it at some point.

Now, not too long after I discovered internet forums and how to navigate them I joined a hobby forum and everything was good for a while but, at some point my usual whatever it is, DID or extreme mood swings or insecurities or something began to spill out and (this happens everywhere I go online at some point.
I just can't control it no matter how hard I try)
My behaviour changed radically and I went from being this really nice, enthusiastic and reletively likable guy to being a sneaky, vicious, arrogant and sinister being who is opposite of everything I stand for.
Some of you have probably seen me post about him on here before and even seen him make posts himself.
For short I call him DH. I'll not go into everything that he is or why he exists but, he exists for a reason that is connected with early childhood trauma.
So, DH once cyberstalked someone on a forum who we perceived as a snob and DH was triggered by other people on that forum who really were behaving like snobs.
Thankfully it never got really bad but, it was bad enough that I ended up apologizing and leaving that forum for good.

Over the years I used other kinds of forums and everything was fine at first but, eventually someone would come along who thought that they could disrespect me or my friends and the whole mess would start all over again but, without any stalking.
The next time DH stalked someone was on an adult forum because that person enjoyed picking fights and even threatened to kill me so, in order to feel safe I let DH (meaning I didn't attempt to stand in his way that time or try to convince him to stop) cyberstalk that person until their full name, city and address was learned. Because of all of that I left that forum as well.

Years went by and later I ended up joining a gaming forum and everything was okay at first until some guy there started trolling me over differences in political opinions.
I tried to ignore him but, he wouldn't leave me alone so, I called him out and we settled it in a subforum designed for that very thing...or so, I thought.
It was never clear who won that little scuffle but, DH took control and pissed the guy off so, he conspired with his clique to harass us back and lure us back into the subforum for settling fights.
It all ended very, very badly and when it was over or almost over he (the guy who trolled me) stepped out from the shadows and glorified himself for hatching such a clever plan.
It was a very upsetting experience for us but, we learned things from it that we needed to learn.
That guy and his clique still run that place and he is a self-proclaimed sociopath but, I'd already figured that out by his behavior and influence over his underlings.
For revenge DH stalked them back and I let him do it meaning that once again I didn't try to prevent him from doing so.
In fact I was all for it and I am not the least bit sorry.

For a very long time after that I stopped using forums all together.
When I did start socializing online again it was on Facebook with family and mostly people I'd met offline.
Again everything was fine for a while until I started letting political beliefs and personal problems loosen my tongue and began to post really harsh opinions and due to stress at home my attitude got worse and worse and eventually everything spun out of control and so, I started looking for a mental health forum to join because of my stress and nerves because I knew I needed help and that's how I came here last December.

A lot has changed with me since I came here and some of it for the better as I had hoped for but, I've gotten worse in a lot of ways too.
Back around January I got pretty upset over something that almost lead to me and DH taking part in cyberstalking again but, eventually things worked out for the better and we decided not to do that and to just let it go.
Today I learned that a friend on here had been threatened with bodily harm by another user.
Whenever family or close friends are threatened I take it very, very personally.
I offered to stalk and harass this person who made these threats to my friend and when the friend logged off shortly there after I thought that I had upset them with my psychotic behavior and disturbing offer and maybe they thought "Oh my God. He really is psychotic and can't control himself."
So, as I sat and thought about it all and about a lot of the over-the-top, insane and dark posts I've made here at PC I came to the conclusion that I really am mad and not just in the angry way.

I've never spilled blood but, there have been times in my life when I wanted to very badly.
I know that I am very sick and twisted also.
I know that my self control is no longer stable.
I will be seeing my doctor very soon. I plan to talk about the things that are on my mind and have written down some things about myself to show to her.
I'm very afraid of the idea of being locked away because I don't believe they will ever let me go again and if I suspect that that is the case then there will be plans to attempt to escape and I'm ashamed to say how those plans will be carried out.

I don't know what to do but, I do believe and have believed for many years because of things that have happened to me in my life and thoughts that I have had that I am a potential homicidal maniac.
There is still much that I have not revealed.
If anyone cares to reply, please go easy on me.
This wasn't easy for me to admit and I'm scared of being judged for it.