obsessive mom?

My mom is lowkey obsessed with me. I have a serious boyfriend  , I'm 20 , both my parents are fairly controlling, I told her we're saving up to get an apartment and she's like NO I don't want u to leave but had no reason why. We recently went to dinner me her and my boo, and as we left my boyfriend and I were holding hands and when she saw she grabbed my other one and started swinging it. Yesterday was his 25th birthday , and on his cake I wrote  "Happy birthday baby"  and when she saw it she blurted out loud " IM YOUR BABY" I was like no you're not that would be weird.. I'm not trying to be mean but she's lowkey starting to irritate me with all this weird jealous bullshit and it's also a little embarrassing ...I want to live my life in peace with my baby..