Look, I can't pretend to have the same problems, I'm a guy. But I'm going to offer a comment because there really aren't a lot of people who participate on here and so I'm not sure you're going to find that many who will respond with similar experiences. But in a way, everyone with mental problems has similar issues -- we may differ on the specific things that terrify us but we're all terrified. But to me, I just wanted to say I think you've already solved your problem, it just hasn't shown up yet in the results so to speak. That last line, don't judge, I've been through enough of that, may just tell you everything you need to know to overcome this fear. Everyone with mental problems feels judged. And it's because a lot of people do judge us for our weaknesses or the fact we're different. You may have a couple of things going on here. For one, there's the religious thing. All religions are based on judgment, even the ones based on not judging (I'm talking to you, Buddhists, that karma thing is pretty judgy). It might be you just never really liked people telling you what you were supposed to be like but felt guilty for that. It's a very common root problem, especially regarding sexuality, with people who grow up religious. It's especially a problem for women, because men get cut a lot of slack for their sexual peccadilloes that women don't. And maybe as well, you just don't want to have children but feel guilty about that as well. That only you know for sure, but I didn't get married until I was older to a woman who had been married to someone else when she was quite young for a long time and never ever has the slightest desire to reproduce. For me it more a matter of circumstance, as I just never got married, but for her it was her choice to not have kids. For her, this wasn't a problem, she's a believer but not a religious person and has no guilt about it. So those are two possibilities. But whatever the true nature of why you think this way, if you can find it, and overcome it, I would guess this will all get easier. Slowly. And to me, it sounds, again, like you're more than halfway there already. All the best.
Very sorry to hear that you have this fear. Here's some information for those interested: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830168/
This is typically treated like phobias and anxiety conditions with the recommendation to work with a psychiatrist and counselor and perhaps incorporate medication. This, of course, would depend on the severity of your fear and how debilitating it is to your life. That is just general information for those who are reading this.
https://www.huffingtonpost.co.uk/2011/03/19/overcoming-tokophobia-fear-of-pregnancy-and-child-birth_n_7392926.html You might find this article to be a worthwhile read.
It sounds like you have a long history of anxiety and it has clearly impacted your life greatly. I'm glad you are trying to work through this now that you are in a long term relationship. I would stay with this approach and become more aggressive in how you treat the condition if need be so that you can overcome this. We wish you the best and hope you stay in touch with us as you work through it.