Mestinon (pyridostigmine) for Myasthenia, why does it seem like I feel weaker & etc AFTER taking it? Yet I'm afraid NOt to take it and get weaker!! what do u think?

Don't stop it. Weakness/ fatigue are known side effects of the mestinon, (pyridostigmine) and you would suffer more if you stop it. Communicate that to your doctor on your next visit or call your doctor's office, you may need dose adjustment or ER form for less side effects, good luck.