Hi there. I'm not in the same situation as I had 33 sessions of salvage RT in 2016 and am now 7 months into HT so I am luckier as I haven't had to deal with both at the same time. I felt tired towards the end of the RT and my coping strategy for that was to go out and walk my way through it and on the days that my head refused to co-operate I gave in and had a nap.
If you are like me and are not used to sitting around then I think that you also feel guilty about just doing nothing and the mental tussle about this makes you more tired. In the end I learned to accept that there are days when you have to do what your body says. Don't forget that at the moment we are experiencing fewer hours of daylight which can affect how you feel.
I have to admit that the HT doesn't tire me as much as the final week of RT did so I take my hat off to you and the other guys dealing with the combined effects of both. I haven't experienced any emotional effects from the HT as yet so my wife is disappointed as she was looking forward to seeing this change - whatever that means.
The good news is that the effects of the RT wore off after a few weeks and hopefully you will adapt to the HT.
Push yourself a bit on the good condition days and cut yourself some slack by resting when you need to without feeling guilty.
All the best.
Kevan