Regarding the '5 year pill', are you talking about the one to lower estrogen levels? There are several. I don't know how long you've been taking it, but if you still feel like it's not agreeing with ou after a couple of months, please talk to your Oncologist and let him/her know. You can always be switched to a different one. I had that experience.
What pain are you having in your breast? Are you having follow up visits with your surgeon? If not, you should do that. I saw mine every couple of months for awhile. I don't remember if you had a lumpectomy or mastectomy, but either way, pain (should be minor) may be with you for quite some time. I still have twinges of pain after 5 years. It doesn't last long.