I’m really skinny but i have a big belly fat

Hi please don’t comment more about loving ur body and other body positivity stuff, i need actual advice :( pls be nice

So i’m 5’3 and weigh 103 lbs, it has always been this way but i weighed wayyy less before. The only constant thing about me is my belly fat, it’s been here for as long as i can remember. It’s just something thats been messing a lot with my self esteem. I’m in my early twenties where i should be having fun and doing whatever i want but i feel so restricted because i cant wear the clothes i want—going to the beach is my absolute nightmare… i always make excuses why i cant come or why i wont be wearing a bikini. It’s messing with my brain so much because all the females im surrounded with have the same weight as me but have the flattest tummies. I feel so alone and ashamed

Im planning to get a gym membership soon but i was wondering what other fitness stuff i could do in the meantime? I’ve never been athletic so i’m utterly clueless

I think my diet is also the problem. I’m an extremely picky eater and I hate eating vegetables. I always eat protein and sodium and carbs and sugar, but i’m working on it. What diet should i do? Should i consider taking probiotics?

I’m not sure if there’s something wrong with my body but some years ago they did find a benign ovarian cyst in me, they gave me antibiotics. Idk if that factors into anything