Body dysmorphia

So I’ve sent shirt-less pics to my gf but I’m honestly quite a fat fuck I think and ages ago I saw her ex and he was quite ripped but just i care more about her then he did but whenever I think about trying to go to the gym even tho I have a small one I just can’t bc just get laughed at ik I will bc I’m a fat fuck I’m going to die alone I fucking know it.