I had major twitching for 2 years straight. It has only recently subsided to about
10% of what it used to be (thank god). I had some what appeared like muscle atrophy at the time which I now believe to be subcutaneous fat that was destroyed by Lyme. It's noticeable in my foot, leg, arm, chest all on the left side. I was worried like you at the beginning too because it happened so fast.
Surprisingly the twitching continues 2 years later but I don't notice much 'atrophy' or more likely fat loss anymore. I assume this can happen anywhere in your body including the tongue. I've had literally every muscle in my body twitch, including intestines, anus, etc. 24x7 for years. I think there are much more likely things you would have noticed prior to tongue twitching if you had bulbar ALS. Swallowing, saliva, voice pitch changes, etc. In ALS muscles twitch because they are nearly dead - and happen after all of those other symptoms are apparent. It's not the same with Lyme twitching which can be an early symptom.
I firmly believe it's caused by the neuro-toxins produced by the dying bacteria that get in the way of your nervous system pathways and cause this randomized twitching effect. This will continue before, after and during treatment. For me it got worse and better in a cyclic pattern during treatment. If you notice it coming in cycles like that you can guarantee it's the same. It will probably spread and move around your body as you treat.
The 100% best thing you can do for yourself is to eat clean and detox - the sauna is one of the best methods and has immediate impact. Forget all those supplements crap everybody is wasting money on. I tried them all - no impact whatsoever. Start doing the sauna and those will decrease guaranteed.
Sweat it out, eat clean, no contact with chemicals or anything else. Don't use harsh cleaning products, stay away from cosmetics, hair product, even use chemical free deodorant. You have to let your body detox.
You will heal, guaranteed.