I can confirm Google driving you insane . It happens... But as far as BFS goes, well.. Something for the doctors to suss out. In my opinion as one who has been in and out of physical therapy for 30 years, I would say it sounds like the PT is working. You're using and stretching muscles that haven't received such treatment before. It causes them to act rather like children, they're tired, wondering why you suddenly expect so much of them and are throwing a temper tantrum.

Your therapist should have explained that, but sometimes they don't. It's perfectly normal for the muscles to be weak and fatigued and start twitching when you're doing PT, even if you are in excellent health. As a weight lifter I'm sure you're familiar with the major muscles and might know a few of the minor muscles, but the PT is focusing on all the little supporting muscles that most people have never heard of unless they've taken a medical course, and ones that are rarely given pressure to preform unless in a PT type setting.

Let them jump and twitch about, and be annoying little buggers when you're trying to sleep, but don't forget to let them rest. PT isn't a miracle cure that will have you set back to right immediately, it takes time, even more time than you'll have appts for and in the meantime your muscles will beg for their much needed rest in between PT exercises. Let them have it, stick with the exercises (avoid Google) and you should continue to see improvement. It might never reach 100% depending on the extent of your injuries, but it will get better. Hang in there.