Is it truncal lymphadema?

Hi, has anyone else experienced this?

Sometimes I get a sort of swollen or firm feeling under my arm where my lymph nodes were removed (I'm 7 years out, now). I feel that it is caused by my underwire bra, as it seems to get better if I go without a bra for a day. I don't like to do that too often, as my breasts are pretty heavy, plus I'm over 50, so they aren't too perky. There are times when my whole underarm is itchy or tender, and I sometimes I will get these tiny little bumps. I get the bumps every now and again, and finally had a dermatologist look at them. Turns out they are full of lymph fluid, so I don't worry about it. My question is, has anyone else had a similar experience, and what did you find that was helpful? I'm considering an alternative to a bra, if I can find one that doesn't give me a uni-boob.

I was diagnosed in 2013, had a mastectomy of my right breast (as my tumor was 11.5 cm), did a full course of chemo and radiation, and a combined 5+ years of tamoxifen and then letrozole, until I couldn't take the side effects any longer.

I appreciate any advice you may have.

Tina