I am not doing well in Engineering and I don't know why. Advice please?

I can’t help it I am really struggling and I think I may just want to have my credits go towards something else. I am struggling so hard right now. I went to the tutor for Calculus and everytime he helps me I find myself messing up on the algebra. I am not that good in algebra. I feel like I hit rock bottom. They say go to college and major in something that is marketable. Well Engineering is marketable but at the same time it is literally killing me. It’s depressing me and I had a happier life at a community college. I never imagined myself quitting Engineering because I want to stay in college but I don’t know where else to go. In my mind I feel as though engineering is the only path I can take in order for me to be successful but it’s killing me.