Anyone else have this issue?

I don't really have emotions. When they come they are fleeting except for depression or sadness. I just don't feel bad about the things I do. I do have homicidal thoughts where I'll get into a really different state of mind and think it is okay to kill another human being. I haven't, but still. Anytime I feel joy it is very quick, then it is gone. I can also cut my emotions off when I want. Something I've noticed recently.*

Any suggestions?

Ive also ive been saying that my guilt is sadness instead of it actually being guilt.

Without sounding presumptuous, it appears that you may have some issues that require professional guidance and or advice. With saying that, i'm not judging your issues/concerns at all. I only say this because when you say, "i don't really have emotions." that suggests to me that you never developed a proper emotional awareness or, perhaps you have but it was skewered by traumatic or problematic childhood/adolescence. You say that you recognize when you have, "negative" thoughts such as homicide. I think it's natural for most anyone to experience fantasies of homicide ( this, however, is just me and i'm not a therapist ) especially given our culture. Considering the types of media that we're surrounded and relieved by, i think it's only natural to think of these scenarios. an example may be...,watching a T.V show about serial killers. It's only natural to imagine how one might do the same actions. Many people make a living off of these fantasies, whether it be fiction writers, comedians, etc..,
If you recognize these thoughts as being wrong and feel they're wrong then i don't think you have anything to worry about. However, if you recognize these thoughts but don't think they're wrong only because it's what society decrees as wrong then you may want to speak to someone about them. Either way, the fact that you recognize that you have a problem with how you're thinking shows that you have a conscious because you do ultimately care about what you do and what you think.

I spoke to my parent and she said she was getting me a counsellor but honestly, I doubt it. I assume she's reassuring herself more than me at this point. I do think there isn't really a good and evil in the world. I feel it is based on perspective. I might think homicide is fine, and honestly, it doesn't bother me unless within good reason, based on what I feel is good reason. While I think murder is perfectly okay you might think it is not.
I can say I have a conscious, yes, but I know what society thinks is acceptable and what isn't and what the consequences are, but I don't care. At the end of the day I know I'll be doing whatever I want to, not to sound like a butt, but that seems to be how I feel for some reason. I used to feel emotions at 14, had a big depression crisis and suicide ideation at that time and other things of that nature. At 17 now and I can cut emotions on and off like my phone. I choose to feel what little I can. I lack so much depth it is odd.