I've never heard of inactive Hashimoto's. How were you diagnosed? If tested at that time, please post results and reference ranges shown on the lab report.
Glandular fever aka infectious mono (caused by the Epstein-Barr virus) lists symptoms you mention such as severe fatigue, petachaie, purpura (looks like a bruise), allodynia (feeling pain by something that does not usually cause pain), skin rashes.
Red_Star brought up a good point about EB, but Hashi's can also cause a rash and other symptoms you mention. So I will address the likelihood of you being hypothyroid, since you have already been diagnosed as having Hashi's. Perhaps by "inactive Hashimoto's" your doctor meant that you were positive for the Hashi's antibodies, but your thyroid hormone levels were still within the so-called "normal' range, so he did not prescribe thyroid med, Which left you with hypothyroid symptoms.
In deciding on treatment, the first consideration should be symptoms that occur more frequently with hypothyroidism, which you have. Second is confirmation with tests for the biologically active thyroid hormones, Free T4 and Free T3. You should make sure you are tested for both Free T4 and Free T3 every time you go in for tests. And with hypo symptoms, and Free T4 and Free T3 in the lower half of their ranges, there would be no reason to hold off on starting you on thyroid medication. I won't go into detail, but there are many reasons that the ranges cannot be used as pass/fail decisions about treatment.
If you were tested previously for Free T4 and Free T3, along with TSH, then you need to get a copy of the lab report and post results and reference ranges shown on the lab report so that we can help interpret and advise further. It is a good idea to always get copies of your lab reports and write on there what meds/supplements you were taking and how you were feeling at the time. These become very valuable references later. Doctors are required to give you a copy upon request.
If not previously tested for both Free T4 and Free T3, then you need to get those done. Along with that you need to be tested for cortisol, Vitamin D, B12 and ferritin. All are important in diagnosing and treating possible hypothyroidism. In view of you having already diagnosed with Hashi's, I am not really sure why your doctor feels the need to do all those other tests right now. In my opinion it is much more important to confirm what I said about Free T4 and Free T3 levels, and get you started on thyroid med. Also, if Vitamin D B12 and ferritin are deficient then you will need to supplement for those to optimize. D should be at least 50 ng/mL, B12 in the upper end of the range, and ferritin should be at least 100.
I expect that you need to start taking thyroid med and get your Free T4 up to mid-range, and your Free T3 in the upper third of the range, and adjusted from there as needed to relieve symptoms. Studies have shown that adding thyroid medication can result in a reduction of thyroid antibodies and can also make a big difference in your symptoms.
So you are going to have to get over your needle phobia and get those tests done. You are also going to have to get tests done regularly for a while. You may also find that you need a good thyroid doctor that will treat clinically, by testing and adjusting Free T4 and Free T3 levels as needed to relieve symptoms, rather than just based on lab test results. Based on your experience so far with your doctor, I think it is very likely that he will not agree to treat clinically, as described. If so, we may be able to help you find a good thyroid doctor in your area. So for now please try to get your old lab test results and post them here, along with reference ranges, and also try to get the tests done that are recommended above, so that we can better help you through this.