Hypothyroid - Fluctuating between Hypo and Hyper

My doctor informed me I am fluctuating between hypothyroid and hyperthyroid.  I am on Synthroid 137mcg and he recently added liothyronine 5mcg.  How long will it take for the liothyronine to make a difference in the way I am feeling?  I am depressed, having hot and cold flashes, unmotivated, tired, not sleeping, having muscle and joint pains just to name a few symptoms.  I am on Synthroid 137 mcg and my latest test results are as follows:

TSH: 0.46 (range 0.40-4.50 mlU/L)

T4, Free: 1.4 (range 0.8-1.8 ng/dl)

T3, Free: 2.8 (range 2.3-4.2 pg/mL)

Thyroglobulin Antibodies: <1 (range < or =1 IU/mL)

Thyroid Periodase Antibodies: <1 (range <9 IU/mL)

Is it also possible I still may have Hashimoto's as I have been hypothyroid for over 20 years? I also am purchasing some selenium, B12, vitamin D and zinc to add to my diet.  Any assistance would be appreciated.

Thanks.

I'm new to this but can tell you that the fluctuation is probably from the dosage of medicine.  I went from 7.8 in November to 0.045 in early January because I was given too high a dosage.  Now I have a rash that itches like crazy but my doctor won't retest me on the slightly lower dose for another few weeks. 

I began with 100mcg of Levothyroxine and am on 75 now.  My husband's doctor started him on a low dosage years ago and he's remained stable with no adjustments needed.  

Instead of adding another medicine, wonder why your doctor didn't reduce your dosage.

There is no one size fits all answer. Answers are typically based on your blood work. Your free T3 and free T4 are in range. Sometimes T3 May  drop in the afternoon if you supplement in morning. Then An extended release may help. Truly you need to work with an educated practitioner familiar with correct thyroid treatment and supplementation to modify your dose and determine what additional testing may be needed. There may be another mineral deficit slowing you down. For example my iron and vit D also stay low and impact my energy. Get someone that really specializes to help investigate further.