hyperthyroid turning hypothyroid

I have been enduring a lot of muscle cramps, muscle twitches or whatever you call it since after i stopped taking inderal (its known side effect) for roughly less than a couple of months now because i am hyperthyroid. after reading articles online, i found that i may now be hypothyroid because hypothyroid patients endure so much more muscle pains than hyperthyroid people. when my hyperthyroidism started manifesting i've had palpitations, hand tremors and the worst of all thigh pains which made it too difficult for me to climb stairs because it felt like there's too much weight on my calves and the pain was unbearable every time i walk up the stairs. after the treatment, the hand tremors dissipated, my heart rate slowed down and i was fine again plus my heart seemed to enjoy the walking unlike before, i have to stop every time due to extreme tiredness especially walking uphill. however, i noticed that i'm starting to gain weight. at first, i was a little delighted that my eyes were no longer bulging, my cheeks looks fuller again, but then, i didn't like the fact that my weight gain would be alongside so many muscle twitches that i can no longer function normally. 

i can't do stretching like i used to nor exercise due to the unusual muscle pains. i am now looking to switch to another endocrinologist because i have a feeling that my overactive thyroid is now underactive because of my weight gain, extreme sensitivity to cold, constipation, sluggishness and the worst extreme muscle pains. i know i shouldn't assume but i learned from another hyperthyroid patient from work that once hyperthyroid, if not monitored by an endocrinologist, the patient has a tendency to become hypothyroid due to over medication. i hated my weight gain because it took me 2 years to lose weight.