My heart goes out to you. I found out about my husband’s sex addiction about 18months ago. I too went through all the emotions you are describing, it truly was the most awful time of my life.
It is really tough but things can get better, if your partner is committed to recovering. 18 months on, me and my husband have a more stronger relationship than ever.
Even now I have bad days, if the memories are somehow triggered, for example even if I go past a massage parlour. That’s why I still visit this board, to find out how others are doing.
I hope this helps somewhat.