Whose the real mother?

I think my mother used me and I'm getting pissed as fuck.

My mother started dating this man named Marvin when I was like 10.  Marvin owned this corner store in my neighborhood and he has a big house and his wife died and supposedly left him some money.  She fell for him real bad.  

Two years ago when I was 15 he dumped her. My mother called him every night and scratched up his car, pulled out his mama's hair, cut up his clothes.  She lost her damn mind over this damn man.  One day, I heard her tell him she was pregnant.  He started coming around more and taking her to her appointments.  When I asked her what was going on she said mind my business.

So, then when she was about seven months pregnant, she start screaming for Marvin.  She told him she lost the baby and they went to the hospital. They broke up again about two months later.  I used to see my mother throw used pads in bathroom every month at her usual time, but I didn't know better.

My mother set Marvin's clothes on fire and alot of other shit.  Marvin started dating Mrs. Annie and my mother was so mad.  She went to bed and would not get up.  I had a boyfriend named Seven and my mother started asking him to have sex with me and telling me to do it and she'd give me alcohol and throw parties.  My mother had always been strict and I was surprised I didn't have to pretend I wasn't with Seven.

Anyways, when I turned 16, I was pregnant.  My mother sent me to Texas to my Aunt's and told everybody I was with my daddy. When I had my son she took him and left me in Texas.  I just turned 21 and I have one more semester left of college, my son is almost 4.  I went home for the first time in nearly 5 or 6 years.  My mother brought my son to see me every year and I tried to do right by him.

When I got home.  Marvin and my mother were married and he is calling my son, "son."  I was about to ask what the hell was going on, when my cousin Tish pulled me out the room and told me:

 My mother bought a pregnant bump online and put it on her stomach, when she found out I was pregnant .  She told Marvin the baby was his and Marvin came around when my son was born, she took my son into the hospital because he was sick and that's how Marvin saw him. Then they got back together and got married on his two year birthday.  My cousin showed me the birth certificate with my mother's name on it and she changed my son's name to Marvin Jr. and his last name was amended to my the birth certificate my mother has. 

I'm a pretty good girl and I know my mother does wrong but I respect her and I just cried and was quiet until I saw Seven three days ago.  How can I not tell him about his son.  My mother told me he didn't want anything to do with me and I wasn't allowed to call him and I didn't.  He said, he heard rumors that I had his baby in Texas and where was it?  I told him I couldn't talk then.  I ran back to Texas and didn't even stay the three weeks I was supposed too. I don't know what to do.  I can't destroy my mother's life, but I want my baby back and Seven in my life.