That sounds frightening. I agree with arpie, meet with the most senior person you can. It could be a reaction to the chemo, muscle spasms and tremors are common enough, but given your past history push hard to get a resolution to this. I'm assuming you had a specialist when you had problems with the previous autoimmune condition, don't be shy about getting a referral back to them. General advice from doctors who are not experts in a particular field is not always helpful, as many of us have found out to our detriment.
Advocating for yourself is very difficult when you feel dreadful, but unfortunately it is sometimes necessary. Mxx
