Hi,
i was in the exact same situation you are. I met a wonderful man who had had a vasectomy 3 years before I met him. He has 3 kids and I have none and desperately want them. We talked about it in depth and he has since had his vastectomy reversed so yes it si possible! The are lots of contributing factors as to what the cahnces of success are but its worth a try. We are still waiting for the final sperm count to be done but he has one a couple of weeks after the operation and that one came back good so fingers crossed everything will be ok.
It's a really hard call to make when like you said you know you are running the risk of never having children by staying with him. All I have wanted all my life is to have a family (i am 27yo now).I thought so hard about it for a very long time and in the end I had to ask myself, is it worth leaving a relationship with someone who I am perfectly happy with to run off and try and find something that I may never find. If I was to leave my partner just to find someone who can have kids, how do I know it will even happen and I may never find someone who I love as much as him. I decided it wasn't worth the risk and decided to stick it out for better or worse so now we'll just have to wait and see. You can p.M me if you want to chat.
I'm sorry if this makes things more confusing.
Best of luck
kylie