It will be tough f where you are but not impossible
It’s really a 3 step process
1) turn up
2) pay attention
3) do the work
By your own admission, you’ve not been doing the homework which breaks step 3
So, you really need to get on board with the plan and also do all of the work you have missed so far. If you broke rules 1 and 2, you also need to go over that missed work also
Going forward, turn up, pay attention (that’s really important) and so the work.
Do past papers as you go and look at the mark schemes. Work out where you are dropping marks and either correct the way you are answering. Or go back and study the content.
Success in a levels is, in part, down to hard work I’m afraid (though having good teachers will also help, supportive classmates, steady home life etc etc)