I have to cite value in the post, above, by VernonJ that warns about all that can go wrong. That's exactly the kind of thinking that I do. (Like I said: I'm not normal.) But I also find value in the post, above, by divine that points out how life-destroying negative thinking can be. I guess the O.P. has to take her pick.

So this guy has "severe depression." He is a relatively young man, I presume, in a 4 year relationship with a pretty nice young woman who sounds quite devoted to him . . . and he is severely depressed. What's his problem? He sounds like a guy who doesn't even want to give life a chance. (He sounds a bit like me.)

One of the reasons I settled on a guy who already had kids is because I did not want to induce some young guy to come aboard the nut-train that I ride on. And I didn't want a guy who was already not interested in normal living. So I picked someone who had racked up normal experiences in life. I don't know what this young man has been through, but he seems to be making a career out of being miserable. He may be cooking dinner every night, but I'll bet he requires a lot of emotional tending to. And, of course, in a household with children his interminable inner angst might have to take a backseat to other more pressing concerns. It sounds to me like the O.P. is enabling this young man in having a very self-absorbed existence that is pretty unhealthy. I wonder does this guy have a job?

So he's had 4 years of feeling his girlfriend how severely depressed he is and couldn't possibly be expected to cope with fatherhood . . . and that's him being true to who he is. Someone ought to tell this guy to "snap out of it."

I don't mean to sound unsympathetic to the O.P.'s plight. Olive, you are in a bind here. You sound way too in love to be even capable of leaving him, but I think, maybe, you are being had. I could see if your boyfriend were suffering from a genetic disorder like Huntington's Chores, which poses a 50% risk of getting passed on to any child. That would be a good reason not to have your own biological children. (Jay Leno has a genetic disorder and opted not to pass it on. I respect that.) I guess I feel so strongly that your guy is on a fast track to staying miserable because he reminds me of me . . . and I see how sad my life has turned out.