I’m planning a life with someone and mom doesn’t know

I’m 19, and my boyfriend is 23. When we first met we were FWB and it was very hard, as both of us suffer from anxiety and depression. During a fight I told my mom about it all and she demanded I break up with him, I told her I did, but we soon got back together. She has no idea. Now, we have been together over a year and are, while not engaged, plan on getting married in 3-4 years. I have no idea how to tell her, as she’s very controlling. I still live with her, though I plan to move in with my boyfriend in a few years. How do I tell her all this?