aw i'm so sorry you're feeling like this. first of all - DON'T APOLOGISE! it is in no way your fault that you are depressed and are finding it hard to work.
what course are you doing now and what course do you want to do next year? is it really necessary that you stay on this current course to get to the more practical course? if not, maybe you should consider whether you will really benefit from staying on.
if you need to do it, then we need to try and make it work for you! first of all, are you enjoying the course or do you hate it? if you're not enjoying it, then in my opinion, there's no much point doing something because you won't be putting in the effort that you are capable of.
do you have many friends at uni? maybe getting out and doing something for a while will allow you to feel better about your essays. if you're feeling upset and putting too much pressure on yourself, it won't help! even if you've found it hard to socialise, even just going for a walk or shopping or anything that you enjoy alone will help! or even just reading a magazine for a couple of hours in bed or watching tv. just ANYTHING that makes you feel good!
also, try not to put so much pressure on yourself. you're not alone, there are loads of other people in your uni that are finding it hard for one reason or another. and if you don't manage to do it or don't do it very well - so what? you can do it again. you can learn from it. it's not the end of the world! maybe even post on TSR to get some ideas!
lastly, try to remember why you're there. you're at uni for a reason. it's supposed to be enjoyable so try to enjoy it best you can and if you're not, think about your other options!!
please feel free to PM me if you need to chat anymore. GOOD LUCK!!!!! xxxxx