Thanks for the answer.
My husbandry has always been the same just like my thawing process.
I've mentioned the temperature and the humidity (at this moment) above. My snake has always something to drink. I don't handle him so that wouldn't stress him and the enclosure is covered up to he can feel at ease. I use cypress mulch as the bedding. I also use two identical hides. This is how my set up has always worked.
Concerning the thawing process: I always put the rat in a zip bag and then I put the zip back into lukewarm water for about 20 minutes until it's thawed out. After that I take hot water at 140 Fahrenheit and put the zip bag in there for like 2 minutes. Normally the rat is just warm enough wafter that.
Also there are two more things I've noticed. My zip bag had a small hole so that the rat was wet when I offered it. That's not a problem since my snake eats it anyway and it's just water. While cleaning I noticed that the water that was left in the bag was brown. I don't think I've seen that before and that's probably not a good sign.
I shouldn't feed my snake for 2 weeks now, right? I'm a bit worried since he is losing weight (he's one year old and weighed about 750 grams, now about 730 grams) but he should be okay. He's a good enough weight to make it through two weeks. I hope it'll be okay.