I struggled with the same thing in school. I would have so many assignments that I would feel trapped and that I couldn't do anything to fix it. This might be bad advice, but it worked for me- work on the small assignments, do as much as you can of the big assignments and try your hardest to finish them, and don't be afraid to know that you might not be able to finish every single assignment ?

How to start doing them? Just get offline. It sucks cuz social media addiction is real and sometimes its hard to get away, but you're going to need to do it at some point. Turn off your phone, keep off of websites you know are going to distract you. Take breaks every now and then, and use those websites or games to reward yourself. I guess its a self control kind of thing, but for me, laziness always got/gets in the way. Don't be lazy

get pick up something and start doing it, as pressured as it might be. Once again idk maybe bad advice but it works for meee