Severe side effects - advice please



I am on Letrozole too coming up for a year soon. I am currently experiencing severe indegestion and other gastro problems (to be fair i did have this before bc dx to a degree, but it has been very bad for a couple of months now). I too have wrist/finger/feet pain. 


For those that have these problems too, could you suggest what/who i might tell.


I am also waiting for a operation to remove a ‘cyst’ in my right ovary, it is approx 6". - They are not certain what it is yet. I have had an MRI


So, all in all I am not feeling too well.