haven't CT gabapentin, but have CT high levels of benzos and opioids at the same time. I've gone through drug induced psychosis and seizures along with all the other fun stuff that comes along the way, stuff just like you mention.
comfort meds can help- but if you're like me having any drug around can be problematic. Advil/Tylenol might help with the headaches. For hot/cold flashes I would take a lot of showers and crank the ac then bundle up/unbundle constantly. It's annoying but atleast you can have momentary comfort that way.
Talking to other people can have a grounding effect, kind of helping to center you and your racing thoughts. Distraction is key... it's going to be pretty hard to actively focus on anything enough to really take your mind off the matter so it's much easier to just distract yourself with things like imgur/reddit, Netflix, youtube, podcasts- things that don't take a ton of effort to consume. Reading and such may be a difficult and frustrating. Hanging out with small groups of people who understand what is going on can help too if it doesn't make you too anxious. I would encourage to maintain contact with at least one or two close friends through the process and let them know what's happening if yo haven't already.