Bad mood and colleagues frustrating me?

I work with some colleagues I can't stand. They keep trying to stick their nose in my business and make off handed comments about how I'm doing the wrong thing and they're going to have to report me to the boss etc.

I had words with one colleague but we mended the rift. The boss did find out though.

I've found myself increasingly frustrated and short tempered with people. Some actions that are a bit out of character for me and just generally wanting to be away from everyone a lot lately.

I've lost enjoyment for life because all I do is work and study. I'm behind in assignments, my wife lives in a separate room to me, she can be verbally abusive, work is short staffed and I'm just hating life right now.

I went shopping yesterday and I couldn't stand all the people trying to go past me in the aisles whilst I was trying to find a gift for my son. I'm quite sure I had an angry face for most of the day. I'm just sick and tired of people right now. What's wrong with me??

I love my night job because I can work alone and driving to and from work is such a breeze because hardly anyone is around on the roads to annoy me as well.