I don't know if this is the right place to put this, or even ask this but I am desperate. This is my first post, I joined to find answers to my problem, so if you need more info, please ask. I don't know how to really explain this without it becoming a hugely long post.

I have an online friend (my only friend) whom I have only known for a month or so. We have talked every day for between 7-12 hours via video chat. There has not been one day we missed talking for at least that long. I feel very comfortable with him, I can honestly say I love him as a friend and we can talk about anything with each other. This person is very important to me but I have noticed some disturbing behaviours/thoughts/feelings on my part. Such stupid little things.
I tend to react emotionally at some things, way more than I should and often at things that shouldn't warrant and emotional response.

Sometimes he will say something and I can feel my mood change and my emotions start to shut down. Or I will get angry and want to leave the conversation. It can be any little insignificant thing. For example, this morning he was asking me about the place I work part time and I gave him a yes answer without elaborating and he rolled his eyes. I could immediately feel my mood shift and I wanted to run and hide. Usually I would have found a way to end the conversation quickly but I didn't this time, I stayed and talked with him but I felt distant the whole time. I did eventually end the conversation because I was feeling more and more uncomfortable.

I do this with everyone apparently but have only noticed it recently with this person. I don't want to lose this friend, so I want to find out why I do this and how I can change it.