You need WAY more testing to really figure out what is going on. TSH is nearly worthless test. It is a screening test at best. With the TSH you got. It should then cause the DR to want to test additional items to get a better picture of what is going on. specifically it would be REQUIRED in my opinion to get the following tests:
TSH
Free T4
Free T3
I would also recommend highly to get the following tested as well.
Iron
Ferritin
Vitamin D3
Vitamin B12
You have clearly shown a side effect or reaction to the T4 medication. Do you know the brand of T4 specifically because there are several manufacturers of this and they can use different buffers and fillers etc. And you could be having a reaction to one of the fillers rather than the T4 itself.
Also you may be a candidate for Armour or natural desiccated Thyroid medication if side effects persist with T4 medications.
Have the Chest pains cause been isolated? That is was it from rapid heart rate or some other cause?
In my wife's case. She and others is fairly common that acid reflux was a result of or a symptom of low thyroid. My wife was able to stop taking acid reflux medication when she started getting sufficient thyroid replacement.
Doesn't sound like that is your situation. But keep in mind that it is often common to feel WORSE for a time when first starting medication. But your report that you tried for 2 months before shows you gave it a pretty good try.
Can you tell us what your dosages of T4 were when you tried in the past as well as most recently. Typical
starter" doses commonly seen are usually not more than 50 mcg per day. So if higher than this it might cause some "shock" to your system and not be tolerated by some people. You might be one of those people.
If you Dr will ONLY stick with TSH and put you on a large initial dose of medication. BOTH would be a sign the Dr is not knowledgeable on Thyroid issues and you would be best served by looking for a new Dr.
Just my thoughts
May be due to some kind of problem with pituitary gland's TSH production or some problem with thyroid gland not responding correctly to TSH value. In such cases its common to see hyperthyroid symptoms appearing when on thyroid medicine but it doesn't always mean not require any thyroid medication. Look for the symptoms when on medication, do you sleeping more during day? feeling cold? etc it may not appear suddenly when stop medication but only after some 1 month or so as T4 have high half life.
Treatment plan is to find a suitable thyroid hormone dose which neither gives you hypo or hyper symptoms. The hyper symptoms might be temporary due to TSH fluctuations. To reduce it the dose needs to be increased in small steps giving sufficient time in between like 4 weeks and close monitor the Free T4 and TSH values.
Also its good to rule out these deficiencies which is common among hypothyroid people.
Vitamin D
Vitamin B12
Ferritin
I had just responded to your first post, so I have copied and pasted it here also.
It may be that it is not the levothyroxine itself, but a reaction to it caused by other problems. Just for example, it is always a good idea to test and assure adequacy of cortisol before starting on thyroid med. Another possibility is low ferritin. It is important that ferritin not be toward the bottom of its range when starting on thyroid med. If tested for either of those, please post results.
What symptoms did you have and what were your thyroid related test results that caused the doctor to initially diagnose you as hypothyroid? Along with the TSH of .004, were you recently tested for the biologically active thyroid hormones, Free T4 and Free T3? If so, please post results and reference ranges shown on the lab report.