Levothyroxine Sodium and weight gain

I have been taking levothyroxine for about 10 years now, i have had the following symptoms with them, weight gain, hair loss, mood swings etc, but i can also put it down to having a Mirena coil. The main thing that has concerned me is that i started to have panic attacks over a year ago with severe depression to go with it, my life was fine before that, had no problems, 3 wonderful children, my life was great.
Does anyone know of any other medication/natural products we can take?
I'm just so fed up with feeling like crap all the time.