How to deal with my thesis chair? I am a 2nd yr Master's student set to graduate this may. My plan is to pursue a PhD afterwards at another institution. In my program, you either have to do a Master's thesis or a 45 min oral summary presentation of what you learned.

I always had the intention of doing a thesis and had a really cool one my first yr. We were collecting data over the summer and everything was going well. All of a sudden, my thesis chair told me she was leaving for another teaching position in a different state. B/c it was not possible to do this without her and no faculty wanted to take over, I dropped the thesis. This occurred the summer before my 2nd yr.

I still wanted to do a thesis, and so I asked a man (who was on my first thesis committee) if I could be his thesis student. He agreed and he had me print articles so I can get started reading over the summer before I started writing my proposal. Summer went by and everything was fine. School started in Aug. (2nd yr) and things were still okay. I had started writing a portion of my draft and had sent it to him for edits. He edited and sent it back. I edited it again and sent it to him before our meeting. He then emailed me, saying he needed to talk to me regarding his plans.

Just as background info, I felt completely dropped and abandoned by my first thesis chair. When I asked my 2nd (and current thesis chair) to take me on, he assured me he wasn't leaving.

Anyways, we meet and he told me he was leaving late Feb. on medical leave and wouldn't be coming back. We decided to continue on with the thesis, but tweak and shorten it in order to be ready to propose this Fall and defend early Jan.

I started to work harder and he would send me edits. We always seemed to get along, and we had a nice flow. However, something in him changed, like snapped. It was like he went from Mr. Hyde to Dr. Jeckel. October came and it was complete radio silence which was SO unlike him! He never responded to any of my emails although I emailed him every week in Oct., he didn't edit any of my stuff, he forgot our meetings. He was just so radically different. After not hearing from him over email, I started to wonder if I had said something. I had texted him (he said I could text him any time) b/c I hadn't heard from him and he sent me this snippy, rude text, telling me not to text him this early.

Because he failed to respond to my emails and give me edits, it was about 4-5 weeks until we met again. Because of this gap in time, it is impossible for me to do a thesis with him.

What gets me is that he went from being kind to me to almost borderline rude. He isn't as nice, he's cold, snippy and distant. The 2 of us talked to the department head and it's decided that I will do the summary presentation instead of a thesis (my chair decided that for me not my decision). 

The summary presentation is like a reflection. It doesn't involve drafts of edits or anything like a thesis requires. It's really easy. Since he doesn't know any of the rules, I've had to explain this to him.

Basically, my question is, how do I deal with him? I'm thinking of switching advisors although I dont know anyone who could take me on. My thesis chair is still demanding that I do lit reviews although it is pointless. He basically is telling me that if I don't do what he says (the lit reviews and other things that is ONLY necessary for a thesis and NOT the summary presentation), he won't sign off on it. I NEED this to graduate.

My question is, what do I do?! I'm usually very calm but lately I've been stressed and anxious, I'm breaking out and haven't taken care of myself in a while. I am perpetually stressed and fear hearing from him. I just want OUT. He's toxic and mean. It's like I'm being held hostage. Please help me.

Also, if people are wondering, I have done NOTHING to him but be nice, obliging, etc. I always tell him if I can't make a meeting and am polite to him. People are telling me it's stuff in his personal life, but I just want him to stop treating me like trash.
The thing that stands out here is that the new advisor is going on medical leave and won't be back. This sounds serious. Maybe he is facing his impending death. This would make his work very unpredictable. 

It sounds like the department head was trying to make the best possible decision for you, though probably shouldn't have done so unilaterally. But starting over again will probably just delay your completion, which I assume you don't want. 

You've been caught in two bad situations which is very unfortunate. Work with the head to find a good way to reach completion and also get good recommendation letters to support your future. 

At least ask if the head can find a way to give some stipend to your first advisor to permit her to continue to work with you. Even if that isn't possible it may get the department head to start thinking of better solutions. It is a situation that is uncomfortable for the head as well.