Sex positions for a large penis

Hi people. I have a new partner who happens to have a huge penis. I mean enormous! About as thick as a mans wrist. And no I’m not lucky because we haven’t even really had sex yet. He inserts it a couple of inches and it stretches too much and we stop. And I’ve had three vaginal births. It’s getting pretty frustrating. he does other things to please me but I can’t really please him as I can’t fit it in my mouth properly or get a good grip for a hand job. I don’t know if there are certain positions that will make it easier for us. What we’ve done isn’t painful so much, more just really uncomfortable.