You say you are not avoiding sex - does this mean that you and your husband are sleeping together regularly, or do you mean that the reason you are not have relations with him is you poor health?
If you and your husband are no longer in a physical loving relationship because of your ill-health, then he certainly does have a problem.
I am not saying you should have sex if you don't feel up to it, but I know how hard explaining to a husband that you love him, but you do not want to sleep with him is. There is no way you can do so, that I have come across, without hurting him badly.
No woman, I have ever met, feels like sex when she is poorly and certainly not with the problems you describe, and it is all very well saying your husband should understand this, but men do not necessarily understand at all, because a man has to be practically at death's door, not to want and desire his wife!
Try to find out what the time-frame for some of the specialists' appointments will be, and try too to do something to help you sleep better. Most of us do need to get up to wee at night, can you not get back to sleep afterwards?
If this is the problem, try drinking lots of fluids early in the day, and don't drink anything for an hour or so prior to bed-time.
Then the more mundane considerations: how old is your mattress? A new one might just help you to sleep better.
His remark may have been made in a fit of pique, but is more likely due to sexual frustration. So you and he do really need to try to discuss this frankly, giving each other time to express your thoughts and wishes.
You may want to consider not taking the HRT advice - with your medical history, you need to ask your GP whether i t would be safe, as I have always understood the HRT increases the risk of cancer.