I try hard to communicate with people, but then when I finally lose my temper they are surprised and offended.

To my mind I had tried repeatedly to discuss and make it all understood.  At times I have believed that I was understood.

In the end nothing was achieved and months passed.

I suppose there are two possibilities.

1) the person did not remember our previous conversations.

2) I cannot communicate well.

I suppose I ought to add a third one:

I can’t succeed at anything.