You should read 'John' by Cynthia Lennon, OP.
It's a breathtaking read.
To my modern eyes, it's the story of a woman in a relationship with a deeply selfish, deeply troubled man. The story of what a woman tells herself about love (with the connivance of society's sexist expectations for women,) that keeps her giving and giving - and sacrificing her own one, good life - to support that relationship.
It's a grim read.
And then, right at the end, she asks herself if it was all worth it.
And she says, 'No.'
It's utterly grim.
Don't be Cynthia.
No-one in a relationship between two adults should be 'coming first'.
Relationships between two adults shouldn't be a competition.
The reason the child thing is coming up is because now - at the moment - your not having children renders invisible the fact that you are devoting large chunks of your material and emotional labour to supporting his life and self-esteem.
That's a mad situation - he's an adult. He doesn't need care like that. And it certainly shouldn't be one-way.
And when you list his positive points - what you feel he/this relationship give to you - what you come up with is your feeling of lack of worth.
Read your replies back.
Honestly, every time you say how great he is, you actually say that you feel unworthy of a relationship for X, Y, Z reason.
You tell us you are not well-off, you feel physically unattractive, you don't have perfect health.
You also tell us you have a history of unpleasant boyfriends.
Honestly, you need to work on your self-esteem.
Loads of women aren't well -off and/or don't have perfect health.
It's OK.
It doesn't mean you have to date selfish, in-giving people and be grateful. It doesn't mean you have to date selfish, ungiving people and then jump through psychological hoops to tell yourself their selfishness is actually generosity and love.
Actually, you need to believe you are worth actual love and care with a person who delights in loving you.
This person and this relationship is not what I would want for my daughter. I would want more.
And I want more for you.
Good luck.