Hi OP, I have been through the exact same thing. I had an abortion at 19 weeks it was the hardest decision I have ever had to make, hence why it took me so long so understand what you're feeling at the moment.
I hope you don't mind me sharing my story but:
I'm 20 years old, a Final year University student and fell pregnant quite early on into my relationship. It was a very scary time for me, my boyfriends family are in financial difficulty so they wouldn't of been able to help with the baby. Both our families are religious so they see abortion as a sin. We didn't tell any of our families, just a few friends.
We went to numerous counselling sessions as we were stuck in limbo and torn between the decision. I was more on the side of wanting to keep the baby.
I decided around Christmas time that an abortion was the best option, as I didn't want to bring my child up on benefits or live in a council house. It's not the type of life I wanted. We thought about adoption etc. But we couldn't envisage giving our baby away. I had a late medical abortion on the 22nd January in Doncaster. I was only given 24 hours to come to terms with the fact I have to give birth to my baby. (Which I wasn't told at my original consultation in Luton). The nurse held up her hands and showed me how big my baby would be, I walked out and nearly changed my mind.
It was a very traumatic experience I told one tablet on the 21st January, and then had to go into the clinic (where I stayed overnight) in which they gave me four tablets (to insert in my vagina) every four hours until the pregnancy passed. It was intense pain didn't deliver until 1:22am and I had got to the clinic at 5pm.
Please take note though at 18 weeks the baby is fully formed, it's no longer a foetus so it will look like a proper baby.
I was going to counselling sessions (after) then they referred me to therapy. However, the therapy sessions stopped because of the Coronavirus.
Obviously this is your decision OP, and no one should judge you for your decision. IMO I regret my decision as it has had an adverse effect on me, I struggle to sleep, my anxiety has hit the roof. I keep thinking what if, but I know deep down it was the right decision.