Fat girlfriend; small penis

My penis is relativly small, right on 5.0" as a result anything other than missionary can be frustrating for me with a thin female.

But, with my 370 lbs girlfriend its impossible, I'm not sure it even works in missionary. It makes my frustrating situation more obvious.

I might have to break up with her. But she's my first girlfriend in 19 years so I dont really want to lose her.

Any ideas on how to bring up the subject of her losing weight?

im preety sure she needs you as much as you need her so thier is no problem with her caring about how big ur penis is...as for her losing weight that is basically impossible and you saying any thing related to her losing weight while u are with her will probally get her pissed and break up with u