Hi and welcome,
Unilateral parathesia is a more common presentation for MS but that doesn't mean it's the most likely explanation......infections would typically affect you all over your body and not just one side, the only thing i can come up with would be a sinus and or ear infection, which could explain the course of steroids and rebound effect a few weeks later.
Both sinus and ear infections can trigger migraines, which would potentially mean what your experiencing could still be migraine related, and with the numbness being in the same locations as you've said you've experienced before with your usual migraine symptoms it makes sense that is could cause you to experience something different too your typical migraine if an infections triggering it..
MS symptoms are caused by 'lesions' in the brain and or spinal cord, think of 'scars' which is what Multiple Sclerosis literally means - many scars......a chiropractor wouldn't be able to do anything that improves or repairs the type of damage to the central nervous system that brain and or spinal cord lesions actually cause, i really can't see a reason why seeing a chiropractor would be helping you if MS was the cause of your symptoms.
Try not to worry, yes i know that's easier said than done but anxiety doesn't help and can actually make sensory symptoms feel or seem worse so it's important that you get on top of your anxiety and not let it run your concerns astray..breath!
Hope that helps........JJ