So there you have it- 'Would I have found the whole deal..unlikely.'
Low self worth? 'Settling'? Afraid of never finding the right man?
I think this is a sad yet also appalling set up.
If (and it's a big IF) he is really 100% gay, you have created not just this happy family you think you have, but a web of deceit.
You're clearly having to lie to your kids, extended families (parents, siblings etc), friends, school gate acquaintances, colleagues, and the rest.
It's living with the lie that is hard to understand.
People will know. Or suspect. You might think it's all under the radar, but it won't be.
How you could lie back and have sex with him to conceive FOUR children when you know he's not attracted to you (supposedly) is impossible to understand.
Where is your self worth?
You could say you are mutually using each other- he's your sperm donor, you're his 'surrogate'.
But it's depriving each of you from what you could have had.
And once your kids find out I'd not like to be you. They may be cool with it, they may walk away and cut contact.