OK Chuck -
I was somewhat out in left field when I said PTSD, but, if you aren't suffering from PTSD after what you just described, then you're Superman. So in addition to PTSD, which I think is still reasonable, you've got failing kidneys and possibly a brain injury from an IED - Am I understanding this now?
Sounds to me like you've given more than your share for your Country, brother. I think it's time our Country did something for you.
I suspect, you
are eligible for a medical discharge with disability. And, you've earned medical care for your problems for as long as you need them. Don't fight this! We (your Country) owe this to you for your sacrifice.
This doesn't mean you have to sit around and let moss grow on you. You can do anything you feel up to doing. Go back to school! Find something that interests you and get involved! Hell, learn how to tune cars!

Your life's not over, unless you give up on it. It's obvious you're not a basket case, but the Marines think you've done enough for them! So do I.
At this point, I think I've gone WAY beyond anything I really know about. I'm simply talking to you as a fellow Veteran and someone who, in a different time saw some things I'd rather have not happened.
Hang in there buddy. Things CAN get better.
- Jack