I'm going to take a slightly different tack than all those who seem to be angry that he even suggested abortion.
I'm going to ask why you and he, after 3 1/2 years of living together as partners, did not already know that one would want an abortion in the case of an unplanned pregnancy and one would want to carry a pregnancy to term, even if it got past hormonal birth control?
Ladies, whether you agree or not, abortion is a valid and equally possible choice, made hundreds of times, for a pregnancy that gets past birth control in a relationship where obviously, if the woman is using Nuva Ring, neither is trying for a baby. He is certainly within his rights to suggest it, or even to expect that this is what his partner of 3 1/2 years, on hormonal birth control to prevent pregnancy, might also want. And, it is presumptious to expect that he would feel differently and suddenly want to raise a baby.
BUT B., where I can completely empathize with you is that he seems to be abandoning you completely, and no matter what your first discussions might have been on the subject, people can change their minds once the pregnancy begins, even if they had previously thought they would terminate the pregnancy. I'm so sorry he won't even talk things over with you. I can understand how depressing and frightening that can be.
Please consider seeing a counselor who specializes in family therapy, and who is NOT religious--you need someone who can help you look at all sides impartially, and that way, if you go forward and have your baby, whether it is with or without him in the end, you will know you made the right decision and will have the confidence that ALL new mamas need. A good therapist can not only help you figure out your own feelings, possibly give you a way to talk with the man you've been with all these years about it, and give you the tools to move forward, but can also put you in touch with support of other women who may be experiencing similar things.