Confused & afraid

Please don't judge. I need to vent. I recently found out I'm pregnant. I was shocked at first but elated. I always wanted another child. My children are 16 & 14. At my age (35), I began to think I wouldn't ever be able to conceive again (not that I was trying but it's been almost 15 years). My dilemma is the father of my unborn child wants me to have an abortion. He is a widower and a father of three(5, 7, & 9). We agreed that we didn't want anymore children (planned atleast), but this is unexpected. He feels overwhelmed as is being a full time father. I love him & his children. But I am torn. I've cried since I found out because I really want this baby. I don't know what to do