Why no confidence!?!?

4 years ago I was blessed with an amazing little boy! He's my world and wouldn't change him.
Before I had my son I was a size8-10, and weighed about 9 stone. When I had him I ballooned to a size 22 and weighed over 23 stone! 😱 After years of being put down by my ex (before and mainly after our son) because I've always been "fat" in his eyes and some others. It upsets me I've had no confidence, but depression and anxiety really make it harder. Since I split with my sons dad (after 6 years) every guy I've dated has cheated or stated the size of me. So I changed things and I've managed to get myself down to a size 12 at 11 stone!! 💪🏻 was quite hard lol, but I still don't feel confident anymore.  A lot of the time away from my current partner and my son I cry over how I look, but I should love myself for how I am but I just can't. But I love how I am now but still want to lose more, but I see myself in the mirror and want to cry, not because of the stretch marks I'm covered in, not the baby pouch or my massively enlarged rib cage that makes it look like I have 4 boobs!!!! Lol. But in my eyes I'm not good enough. My current partner tries to tell me I'm perfect etc... But thanks to my past and how I've been treated I can't accept them. 
I guess I'm asking anyone have any tips to help overcome this? As I should be "BOOM BABY I ROCK!" But I'm far from that. Xxxxxxxxxxxxxxx