Anecdotally, a friend of mine was on a diet and exercise regime, then at some point he switched to Mounjaro to reduce cravings, while keeping the same diet and exercise regime (he's a data geek so he documented things pretty well), and his muscle gain maybe slowed a tiny bit, but didn't reverse on Mounjaro.
Sample size of one, but at least it's not zero.
And, it takes me a day or two to get past a processed sugar addiction. After those couple of days, the body starts getting used to not having that "crack" energy source be a part of its desire-base.
Good luck, stavros, you can do it! And the sooner you start, the quicker you can get over the initial hump of resistence. Perhaps you can carrot yourself along by knowing that you WILL feel much, much better as the pounds start coming off and your body starts being able to walk a bit further or lift a few more weights. Fight the food inertia, my brother.
If you really want extra help, contact the Creator of the universe in the morning and evening, and ask It for help. If you do that with an intention to be able to better help others, you will find that the universe, itself, will become your ally.
I cycle frequently and the impact of the weight loss and added strength has made me feel much faster this year (and it's still rainy/cold season).
GLP-1s might enhance this effect somewhat, but there is nothing definitive.
Adequate protein intake + resistance training can fully counteract it, however. I've even added significant lean body mass while losing fat while on GLP-1s.