Difficulty in waking up for fajr salaah and anger management

For a long time I did not follow much of Islam, in fact, very little. I made a very major sin last year @ the age of 34 and that was my turning point. I had gone from praying one salaat every now and then and if I did two on the same day that was an improvement for me. Since my major sin, I'm praying four salaats a day. I tried five, but I think I was praying too much too quickly. So, I dropped back from five to four. Once I'm able to do my salaats with ease I will add the final salaat which is my Fajr prayer that I find most difficult. Since then I have tried to lead a better life and hope to return to Allah Ta'ala in the best of conditions Inshallah.

My question is that the more salaats I am praying, the more angrier I am getting. I am very quick now to overact and my anger escalates very quickly and I know for a fact that this is not me... the less I followed of Islam I never ever used to get this angry... Infact I would always practice being calm in all situations. The regular anger that I feel now would only happen back then when I was pushed to the limit. I don't know what to do. Please explain to me what is happening and what I can do about it.