I want my boyfriend to get a vasectomy?

ok here is the story, i don't want kids never liked them never wanted them, my boyfriend knows this ever before we started dating and he has had plenty of options to walk from the relationship if he wants kids but he would prefer to have me in his life. i have been on contraception after contraception and have had some dangerous reactions from them and even tho we used two types of protection, i am after an abortion and im about to have my second one and my boyfriend refuses to have a vasectomy because some day i could get hit by a bus is what he tells me his excuse is oh and he thinks in his own head vasectomy and castration are the same thing in his own head. before ye go on at me yes we have used condoms and no adoption is not an option as there are high risks that the child would be born with birth defects that runs in the family two of my own siblings have died from this ,im too young to have my tubes tried, i have been told at my age it would lead to at-topic pregnancies. so i don't want to live a life of fear that this is going to happen again i just want to know if it is the right thing for me to be asking of him. am i being the selfish one or is he