Hoooo boy, yeah, from my experience, 800 calories is definitely too drastic. And the amount of protein you're taking in is plenty good. IIRC, the minimum recommended is like .61 g/lb, so .7 is great. But yeah, I get it, I'm right there with you on getting things to where you want them to be like yesterday. When I'm trying to get back into the gym, I'm fighting myself the whole way to not get impatient, reminding myself before, during, and after, and still I find myself every time getting pissed immediately. I know I expect too much of myself at a pace that just isn't physically possible, so, hard relate to constantly having to readjust by telling yourself to chill. It feels like I'm dragging myself, kicking and screaming, back to reality over and over. I know you already see it a year in, but don't forget to remind yourself that the hard, sustainable work is worth it all along the way, not just in the end.

But yeah, I'd keep the calorie deficit at a maximum of 500 when cutting if you want to maintain muscle mass/strength. Biology is fucky, though, so you may want to keep an eye on things anyway as the rules for even your own body can just change. Anyway, I think you're doing great already, so keep up the good work. Always happy to help in whatever capacity I can.