Scale rot! Need advice.

[Homebody]

I also just wanted some reassurance that his condition isn’t life threatening. From what I have read online, I am terrified that things are too late already.

I don't think that's scale rot. Scale rot comes from keeping your snake in a damp and dirty enclosure. If you aren't, then scale rot's unlikely. Your snake's scales also don't look shriveled like the photos of scale rot I saw online. Even if it is scale rot, it's a mild case. Clean the enclosure (as you have already done), dab a little diluted betadine (povidone-iodine) on it and it should clear up soon.

Also, I'll agree with Boger that your temps are too low. This forum has an excellent care guide that's worth a read. I know you've been keeping for a couple years, but it's a good idea to look back at care guides every now and again to remind yourself of the basics. Good luck.