Levoxyl and pounding heartbeat

Extreme fatigue /bordering on Narcilepsy- falling asleep while driving or at work sitting in my chair. Weight gain despite all efforts (working out and eating right). Rapid, pounding heartbeat. Can't concentrate -easily distracted.

Period is irregular and very heavy during some days.

I have told my doctor about these symptoms but she says there isn't much she can do. I have to wait until I see a specialist. It has taken me 3 months to get in to see one. If the specialist says that I have to keep taking this drug, I will stop taking it and find another doctor.