I need some advice please!

So me and my boyfriend been together for a year, he cheated on his ex to be with me now we’re together and he’s suppppper clingy! He needs me to see him right after work and talk to him 24/7. I am turning 21 in a few, and talked about buying my first alcohol drink and he’s like oh drinking isn’t anything and so against anything I talk about with having fun. My dad just recently passed, and he still wants me under his arm and not spending time with my mother who I live with. I’m only allowed to talk to him or he gets mad and says he doesn’t talk to anyone else (my same sex i’m talking about). Advice? Why is he being like this? He checks all my social media constant because he has my passwords. Whenever I try to go have fun with him itsa issue. Help? I’m only 20! he’s 23!