Nope it's not about not enjoying your future life. If HRT isn't working: and it isn't a cure but 'replacement': then making sure that you have a good exercise regime and healthy diet is important. The brain requires sustenance, sadly it's up there: out of sight, out of mind, literally
How long ago were your treatments? Sometimes it can take a while to accept a diagnosis, treatment and recovery: when I was discharged, that's when I felt bereft of support! No longer a routine for radiation treatment, no more follow up appts. etc..
Do U have hobbies? How often do you get into the 🌞? Have U had your VitD levels checked recently?
Depression can be treated with appropriate medication, without mine I wouldn't get out of bed of a. morning. I was diagnosed with cyclical depression in the early 1990s and have taken various ADs since. I also have an emergency anti-anxiety tablet.
I don't tell anyone that doesn't need to know about my medication regime. I wouldn't tell them when I use the loo ;-).