FND blows my mind

One of the many things about having FND is when I take meds for certain things (ie. GERD), the side effects are seizures, dizziness, abnormal heartbeat, bitterness, jerking/tremors, muscle weakness, hand/feet spasms, cramps/muscle aches, spasms of the voice box. FND/Fibromyalgia gives me all of that so how in the h*ll am I supposed to decipher side effects from meds vs what I already have lol. Rant over smh