Oh, I do feel for you

I've suffered from several bouts of depression/anxiety in the past, and based on experience, I'm going to reiterate the suggestions that have already been made.
Exercise: I am sure that the last thing you probably feel like doing is working out, but it doesn't even have to be that much - just getting outside if you can, taking a walk, will help in the long run.
Diet: eating well definitely makes a difference. I lose my appetite when I'm depressed. Others over-eat. Either way, try to eat as healthily as you can - whole grains, fruits, veggies, plenty of lean protein etc. And don't forget CHOCOLATE! A common brain neurotransmitter affected by chocolate is serotonin. Serotonin is known as an anti-depressant. One of the chemicals which causes the release of serotonin is tryptophan found in, among other things, CHOCOLATE! And bananas. But most importantly, lots of chocolate!

Counseling: certainly an option worth considering. My own depressions tend to be self-perpetuating: I become trapped in negative thought cycles and behaviors, and can't seem to find a way out. For me,
cognitive behavioral therapy was particularly helpful in identifying these negative patterns. Once I was able to identify them, I began to evaluate them objectively, distance myself from them, little by little. See them for what they were: learned, negative behaviors - not an actual PART of me. For me, this has been key in pulling myself out of my depressions.
Finally, don't be too hard on yourself! You have a lot on your plate, so allow yourself to feel bad from time to time without feeling guilty. You don't need to wallow in self-pity, but you do need to recognize that it's okay to feel like you do. I know it may not feel like it right now, but you WON'T feel like this forever, I promise

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