Get a cup of tea, this is a long one. First of all: I've got a pretty fragile head at the moment and I realise there's something not quite right about my emotions, ie: I cry randomly and don't really know why, find small things make me irrationally anxious and can't really "get hold" of myself if that makes sense? I don't want to use the word depression because I'm not sure if that's what this is, but there is definately something not quite right.
Anyway, the email:
So at the moment I'm on a team at work, being managed by a first time manager (we'll call her "B") who's been recently promoted and has a lot less experience in the field than I do. I'm only 25 so it's not like I've got 20 years on her or anything, and although sometimes it can be awkward I've been coping with it fine and I've just kept my head down.
Anyway:
Last week I had a 1:1 with B and she went through some feedback she'd had from one of my more senior colleagues about me. She made out it was a MASSIVE problem and I think because of where my head is at the moment I had a major panic and worried about it, so I went home for the weekend feeling like I'd fucked up my entire career.
On Saturday night the feeling of utter panic hadn't lifted, I was unable to sleep and couldn't pull myself together, so rightly or wrongly I emailed my managers manager (we'll call her "J") and asked her to clarify exactly where I had gone wrong etc. It being the weekend she didnt reply.
Anyway, on Tuesday I got an email back from her where she clarified my points, gave me some more feedback (that also panicked me) and then I just sort of left it. The feedback she gave me in addition to the original feedback from B tipped me over and I've been on the edge of tears all the time im at work since then (seriously as I'm writing this, it's not right is it?)
In the meantime I emailed my senior colleague to talk through the feedback I'd been given in the first place, and he said it was absolutely nothing to worry about and he was really shocked it had been turned into such a big deal by my manager 
Yesterday I got an IM from my managers managers manager (we'll call him "C") asking if he could "have 5 minutes".... so yeah, more panic. I was in a different office so worried all day and all night about it, then finally he called me into a meeting room at lunchtime today.
He basically cossed me for going to J about my conversation with B, and told me I should be offering B as much support as I can and not "trying to undermine her".... 
Essentially, J and C have had a conversation and decided between them that I'm trying to undermine B and make her out to be a bad manager.. which isnt the case at all (and I stressed this), I just needed reassurance and clarification from J that I hadn't damaged my career etc. I feel they've automatically assumed I'm unhappy being managed by B, which isnt true! This has left me feeling really helpless and since lunchtime it's taken all my energy to stop myself crying (I very nearly burst into tears in the "chat" with C but just about kept my shit together)
So now I think I've REALLY screwed up and I'm now going to have a reputation as a backstabber even though that's not my intention at all
I feel like potentially, my mental health situation could be partially responsible for me sending the email in the first place and my ability to make decisions has been really compromised?
What's worse if for the last week I've had a "balloon" feeling of anxiety in my chest and last night I drove home crying my eyes out and couldn't put my finger on why... I think I might be having some mental health issues but I'm not sure?
Am i going to need a new job now? is this going to follow me? Perhaps more importantly, is this depression?