I'm sorry you feel so down on yourself and you recieved great advice so far. Are you recieving treatment like therapy o rmedication. Everyone has moments in their lives when things aren't going well and we have to depend on the kindness of others. I agree you're currently not seeing things clearly because of your depression. You shouldn't evaluate your success or lack of success when you're at a low point.

ATM you need to be patient with yourself and take things one step at a time. I know of one positve thing - you're incredibly lucky to have an ex GF who cares enough to help you - that's awesome, so try to be grateful for this. Treat yourself like you would a good friend, therefore don't mentally or physically abuse yourself. You can get through this with some help and patience. Please contact your doctor and I hope you feel better soon.