Down and depressed

Hello I started on tamoxifen for a few months and then was put on Letrozole after I had my ovaries removed. After 3 months I was taken off Letrozole due to severe side affects of joint and muscle pain I had a 3 month break which by the end of 3 months I was back to being able to go for walks, do stretches losing weight all the things they tell you to do to help reduce the risk of cancer coming back. I was then put on exemestane I took this for four months and even though the aches and pains were not as severe as the Letrozole they were increasing and happening often so have stopped taking the arimidex. I am now back on the tamoxifen and it’s been just over a month I have been able to go on my walks and do stretches, I have had really bad fatigue though and usually when this happens to me I go and sleep and would be ok the next day but this fatigue now lasts for days, I get depressed about this because I can not do anything and I am feeling very stressed out as I really don’t want to keep living like this for the next five years, I am trying to do all the right things to help my chances in surviving but the hormone blocking treatment would no doubt be the hardest part of my cancer journey for me ,,,, please someone tell me there is light at the end of the tunnel....