My long story...need advice

Sorry it's long I will try to shorten it as much as possible. When I was 18 I had my son who is now 6. About 6 months after he was born my bf at the time (his dad) introduced me to pills and I ended up becoming addicted. I wasn't taking so many that I was dosing off but I would have to take one or two pain pills every few hours or else I would feel withdrawals. It continued this way for about a year and then he brought home bath salt. For those who don't know what that is it's something they used to sell at gas stations behind the counter it was kind of like that fake weed (k2?) I forget the name of it only bath salt was like fake cocain. They called it bath salt so it could be legally sold but it was a white powder you snorted and it would give you tons of energy. I figured if it was sold at gas stations then it would be harmless but it ended up being super dangerous and we became addicted to it for about 6 months until one day I overdosed and had to go to the ER. I ended up telling my parents everything and we decided I should get help so I went to rehab for a bit then went to meetings every day and haven't had any pills or any type of drug in years. While I was in rehab my parents were afraid I would relapse when I got out so they requested I sign over temporary rights of my son which was devastating but I understood why they wanted me to so I did. Years later and like I said I am clean and have a good relationship with my parents and son. I live with my mom and have since I got out so I could live with my son and now we are all stronger than ever and everything's how it should be. I met my now boyfriend over a year ago and he's the best man I have ever met. We didn't use protection one night and now I am pregnant. The problem is is I don't know how I am going to move out with my bf since my son is so attached to my mom and has lived here most of his life. I am afraid my mom and him both will be devastated but I have to move out eventually since I am having my boyfriends baby. Idk how to tell my mom I am pregnant even though I am old enough it's still scary after everything in my past. It wasn't easy writing this because I am ashamed of my past so I am sure I'll be judged but I figured maybe someone has helpful advice or encouraging words for me. Sorry again for the length.