Hi Nicole,
I'm Jeanette, mtf, 64 and it's been 4 month that I've been on HRT. I appointed myself as unofficial greeter for Susan's Place, so welcome, welcome to Susan's. Make yourself at home. Come in and have a seat, relax and read the posting of others. Comment on the ones you feel like and post your own questions,
LOL, I guess you did already. Yep, it sounds like you are starting to see the results of doing HRT. Tender lumps under the nipples is the start of your breasts growing. You will also start to notice fatty tissue being deposited in the breast areas along with it and the lump gets bigger. How long it will take, how big you'll get, how fast they grow, all that is dependent on your genetics. Mine after 4 months are becoming noticeable under my t-shirts now. I can pretty much fill a 40A cup bra now and definitely cannot go shirtless at a beach now. YMMV of course.
As for reversibility goes I would think that once you have grown the firmness lumps under the skin that is actual breast tissues you have hit that point. It may shrink some if you stop HRT but it won't shrink much and then your'll need surgery to remove what is left if that was your desire.
I am sure you will get more answers from more of the denizens here at Susan's and there is a lot of good information online. Some can be found right here in Susan's Place by perusing the WIKI and LINKS sections above.
Once again welcome to Susan's.
Hugs,
Jeanette