Advice. Pregnancy. Abortion. FWB

So Ive secretly been sleeping with my best guy friend for about 6 months now. Secretly because we never wanted a relationship as such and all our friends are mutual so just made things easier. However I recently found out I’m pregnant. Now I’m in no position to have a child I’m 18 no money lack of support at home and he’s the same. However when I told him he was so immature about it like making it into a joke I just don’t think he understands the severity of having an abortion. Anyway he agreed to come with me but I booked the appointment at the soonest possible date and now he saying he can’t make it. He has and orthodontist appointment and a football match that evening. I know he wants life to go on as normal and of course this isn’t exactly ideal timing and fitting int my schedule either. Am I right to be mad that he not prioritising me and this situation. I literally want to scream and cry I have no clue what I’m doing I’m really scared and I wanna tell someone but can’t. I feel like no he’s not my boyfriend but as my friend he should still be there for me. I don’t know how to get him to understand. Any advice would be appreciated.