At what age are you able to make your own decisions? i am 19 and I feel like I am being controlled way to much by my mom and by my family?

When you became mature to understand the thing you are able to make your own decision

It's a very huge topic! The way you say "Controlled"  it depends what you really call controlled, cause we have two way & sometimes people confuse & have no idea what a real controlling sounds like, but anyway, in a natural way, that's what families do. I mean first, they are always concerned about you then second is they always want to make sure that you making the right decision. The cycle gonna be repeated for everyone maybe less or more but it'll be there cause that's one of particular feelings of being a parent.

Then, in a legal way, you should be taking your own decisions now & also be prepared to face the consequences, but if your parents involve in your decisions a lot that means they don't believe you can stand by your decisions yet & there's something you need to really understand (as I don't know the story in your life). So giving advice is really different with everything being decided for you & instead of you, advice is okay, but if they decide instead of you but you consider yourself as someone that can handle his own decisions, then I guess you're gonna have to prove it, be responsible for your life & show your parents that you're mature enough to make your own decision.  Talk to them though, show your maturity & earn their trust.