Clough is so right. While you may feel it's not worth the effort to do what needs to be done to see a counsellor, I truly hope you do. You are not the first, nor the last that is going through a rough spot.
Sometimes, being in this depressed place, it is easier to remain there, than it is making what seems to be, a huge effort to get your life back on track. I understand, as I've also been off and on medication for PTSD among other things.
When you aren't feeling good about yourself, nothing feels right. School, friends, the future. Being alone, and/or choosing to be alone, is the lonliest place on earth I think.
Not to mention that you lost a very good friend, and we've seen that many times here in this community. The results are devastating. Losses are enormous, and it is hard to cope with the hole left in your heart, and in your life. Being depressed on top of that, only adds to the pain of grieving.
I do hope you will make just that one effort this week, get your papers in order, arrange to see a Doctor, and be really upfront and honest about all the symptoms you note in your original post. Added up, and talked about, I'm am 100% confident that there is help for you, and you will feel better getting through these days.
Please let us know how you made out.