Keep maths! When I first did quads/sim equations I was horrible. Couldn't do anything. If you really want to do engineering- I mean really- then I'd say push at it but push harder. Once you drop bio you'll have more time. Find someone who can explain the maths for you, or like mentioned previously, google/youtube/etc. Those work perfectly. Also see if you can have a sit down with your teacher and if they can explain things to you. And practice is key, that's for sure. Don't give up till you got it, pal.