As long as you feel okay at that dosage, I would stay on it while building up the ferritin level. Once you have taken your iron supplement for a month or so, if you feel the need, you could raise your Armour dose. I expect you will need to do that since your current doses are not typically enough to relieve all hypo symptoms. But everyone is different, so just take what you need to feel normal.
It is important to understand taht a change in T4 med takes about 4-5 weeks to be fully effective in serum levels. So you should not be changing your dose before at leasst a month. Further, symptom changes lag changes in serum levels, so you need to be patient with med changes in order to fully realize the effect on
At 50 mcg of T4 and 90 mg of Armour, you are taking a total of 107 mcg of T4 and 13.5 mcg of T3. Those doses should not be enough to cause the symptoms you reported. Which makes me wonder if your ferritin being less than optimal may be a factor. To raise your ferritin I suggest a CVS product called Iron plus C. It is a relatively inexpensive generic. I suggest taking one pill (65 mg of iron) each day until you next test your ferritin level.
So what doses Of T4 and Armour are you on now? And how long at those doses?
Those three additional tests are very important for a hypothyroid patient, so please make sure they do those for you. For best effect D should be at least 50 ng/ml, B12 in the upper part of its range, and ferritin needs to be at least 100. Deficiencies in either can adversely affect symptoms.
OF course everyone can have different thyroid levels at which they feel "normal". You mentioned having a number of typical hypothyroid symptoms. Your FT3 and FT4 taken together are somewhat lower than needed by many hypo patients to feel normal. You can address this either by increasing your Armour dose or by adding some T4 to your med regimen. In figure 1c of the following link you can see the effects of T4 dose and FT3 level on the Probability of having hypo symptoms. The red line represents the effect of FT3 at about 8% of its range, green is about 39%, and blue is about 57%. So this indicates that FT3 needs to be over mid-range for full effect with lower T4 doses.
The all important thing is that your meds should be adjusted as needed to relieve your hypo symptoms, and not based on lab test results only. If you want to understand more about these issues, I recommend my paper in the following link.
First thing we need t know is whether you took your thyroid med in the morning before the blood draw? If so, what time and when was the blood draw?
Also are you taking any Vitamin D, B12 and iron supplements? If so, how much daily?
What time of day did you take your Armour dose of 90 mg? What time of day was the blood draw for those tests?
Symptoms are even more important than lab test results. From this Mayo Clinic list of typical hypothyroid symptoms, which ones do you have?
Increased sensitivity to cold
Constipation (have to use laxatives or fiber)
Dry skin (need to use skin creme)
Elevated blood cholesterol level
Muscle aches, tenderness and stiffness
Pain, stiffness or swelling in your joints
Heavier than normal or irregular menstrual periods
Slowed heart rate
Enlarged thyroid gland (goiter)
Have you tested for Vitamin D, B12 and ferritin? If so, please post results.