Hello 'IHATECANCER',
sounds like you and your dad are doing the right and best things. Best of luck throughout the ordeals.
I had prostatectomy 01/2022 but had a spot on a rib so two years of Lupron. Luckily, I got my last shot of Lupron 01/2024, two years worth. My PSA has been and is - and hope it stays - negligible. Hooray!!!
But now I'm waiting for the lousy hot flashes to subside. My oncologist says Lupron doesn't have a "Half-life" so there's no fixed time for the side effects will subside. I'm trying to wait patiently (or not).
And he said it takes time and the older you are the longer it tends to take. I'm 77 so your dad has a 10-year advantage on me; I hope he can follow the same course of "just" a couple years of shots.
Also, I started taking paroxetine a ways back, and still do. It helps reduce the flashes intensity and lower their frequency.
And encourage him to keep active! Muscle loss is another of (my) side effects. So fitness class, lawn, volunteering, and spoiling grandkids (5, 8, 19, and 21) are priorities for me.
Good luck and my/our prayers. Tell him we're all brothers in this constant fight and join us in praising the Good Lord for the skills and tech our doctors can provide.
And you are the "good kid" to stick by him and help him in this battle.

(And my GrandDaughter's wedding? - the young one is now only 5. Great idea so I'm going for it!!!)
Blessings,
Bob