Taking Calcium and K2 might help, but check with your GP that this is OK for you. Not everyone can take calcium, and K2 interferes with some other drugs.
If you have significant osteoporosis and you're not on bisphosphonates or Denosumab, you might talk to your clinicians about these. They stop your body from operating the calcium replacement cycle which your bones normally do, and there are down sides too.
You might also discuss any measures which might increase your estrogens, since it's actually a shortage of estrogen (which is made from Testosterone in men) which causes bone issues. It's not done in this country as far as I know, but in the US, estradiol patches are sometimes used for this. (We have the PATCH trial here where higher doses of Estradiol are used as the hormone therapy, but that's not the same principle.) Increasing estrogens will increase chances of breast gland growth, but providing you're not using them as your hormone therapy, you should be able to take Tamoxifen to prevent that, and Tamoxifen doesn't prevent estrogens acting on bones.