If you wish to lay on your back, put a few pillows under your bum. It'll assist with access.
If you're not happy using condoms then stick to activities that don't require them. There's a heck of a lot that we can do together that doesn't require vaginal penetration, or use a female condom, which in your case that might work out nicely.
Then find someone with experience who doesn't mind seeing bigger guys. Some females have issues with men being very heavy but most do not.
We'll know what to do from there.
Is this what you were asking? For some advice? Not quite sure but hope this helped.