When your other doctor said you were “fine” - did you actually get a copy of your test results? There’s a lot of evidence that shows that thyroid levels noted a “normal” by many labs really are not… so you very well could have been Hypo back in Feb and the doctor just didn’t call it. A lot of lab ranges are from like .1 to 5.5 or 6… research suggests that something more realistic is .3-3.0 and if your TSH was on the higher end of that you would have been Hypo but not diagnosed. Most doctors aim to get your TSH to around 1-2 while on replacement. Most people feel better the closer to 1 they get. My last TSH was 2.0 and I still feel fairly lousy.
See if you can get a copy of your test results from Feb, as well as your results now. You might also ask about having tests run for thyroid antibodies to determine if it’s autoimmune. If you never had anitbody testing (GAD, ICA, IAA) to for sure determine which type of D you have this might be a good opportunity to get that done as well.
There is a relationship, with both being metabolic disorders. There is a stronger correlation between autoimmune diabetes (T1) and autoimmune thyroid disease (Graves and Hashimoto’s). Being hyperthyroid can cause slightly elevated BG levels, but to my knowledge being hypo doesn’t… I could be wrong, so no, it wouldn’t “make” you look like you have diabetes if you don’t. Hypothroidism can really mess with your lipid levels though… I’d get those checked. Edema is also a very common symptom of being hypo… but it’s usually peripheral edema (hands, feet, legs, etc).
Treatment is just a pill you take daily, but the level you need doesn’t always stay the same, so it’s important to monitor your dosage. Some people also don’t react very well to only T4 replacement, and opt to either add synthetic T3 (Cytomel), or switch to a natural thryoid preparation like Armour that includes T4 and T3. As far as I know it doesn’t get any worse than that.