New realization

I'm hoping someone has some insight here. I'm 38 years old and having some major marrital trouble. In therapy and randomly during the course of every day I think about my mom. She died when I was six and I have almost no memories of her at all. In fact I have almost no childhood memories. I know that at no point in my life was her death sufficently dealt with. I've probably had less than 2 hours of conversation about her in my whole life. It hurt my dad so bad that he couldn't discuss it. I'm also told, of course I don't remember, that my little brother who was 18 months at the time recieved most of the attention after moms death. I'm also told that my first stepmom was a little hard on me. in my adult life I have had major insecurities about holding on to women. Not attracting them just holding on to them. I've prdominately been single. I used to drink way too much. I've relied far too much on internet porn. I've slept with a married woman. I've always expected my relationships to end. Emotionally I've stuufed everything in the closet. Out of sight out of mind. Can I attribute my relationship insecurities to the handeling of my mothers death or is it not that simple?

Sure you can. Not just her death but all the experiences you had before and after. It sounds like you were left adrift after your mom's death, no anchor attached.
There are a lot of good books out there about attachment. Depending on the type of therapy, early childhood development, attachment, loss/abandonment, are all very important in learning about who we are.
If you like to read, here are a couple of books I can suggest.
This one I'm currently reading and I really like it: Attachment in Psychotherapy by David Wallin (newer and available on Amazon) and The Gift of Therapy by Irvin Yalom.
Both are fascinating and not difficult reading.

Yes I think you can attribute most of your relationship problems with women from your mom's death but you can get help. Are you married now?
My dad died when I was 2yrs. from stomach cancer and the only memory I have is when they removed him by ambulance from the house. In those days there wsn't grief counselling for kids, like now.
There are very important bonds that are made when we're children and yours was broken therefore you grew up not being able to trust enough or not expect any lasting relationships. I really think you should consider therapy to explore this, so you can have happier relationships.
I also volunteer in the Q & A section of this website and I wanted to caution you about watching porn. We've had several young men complaining about sexual dysfuction because they're watching too much porn. It's possible to become desensitized and loose the ability to become stimulated by regular sex with a partner. Think back to the frist time you saw porn and how easily excited you got. If you were to go back and watch what you watched the first time - I bet it wouldn't do a thing for you. I read several cases where young men suffer from ED because they can't perform with their partners anymore. I just wanted to let you know that this can happen. I don't think that most people know the real danger it has on their sexuality.
Best of luck to you.

Sounds like you might have "I'm gonna leave you before you can leave me" because "I am terrified of getting attached to someone and needing someone because they may not be there for me."

I have that too.