How long were you on the dosage that got you from 9.xx to 1.02? When I was first muddling through all this, I was taking a dosage of .125 and I felt pretty good. However, I had my TSH tested and I was at 8.xx. I felt darn good but, obviously, my doctor was unhappy. I did ONE dosage adjustment up to .137 and within 8 weeks I was hyperthyroid and I had to tweak the .137 so I could get in the correct range.
So if it's only been 6-8 weeks since your last check, the TSH plummet isn't really too fast.
A TSH of 1.02, provided all the other numbers in the thyroid panel are within range, is a very good TSH to have. I used to hear that 2.0 was considered desirable for conception. That was before they lowered the normal range of thyroid levels so I'm not sure what is "optimal" now.
What I will say is that ANYTIME I've gone through an adjustment in meds, whether it be upping my dose to take more, or backing off, it is pretty rough, emotionally. Luvmarypoppins has just posted about her drop in dosage and, within 5 days, she wasn't feeling right at all.
Remember that thyroid hormones are VERY powerful and tweaking them affects every organ in your body. One of my doctors told me a long time ago that, even though my TSH may be "right" at some point, it often takes the organs in the body 6 months to "catch up" to that. Of course, I was fairly hypothyroid and damage is done (temporary) to the body when you are hyper or hypo. It takes the body awhile to repair. When he told me that, it didn't make a lot of sense at the time, but after going through the ups and downs for so many years, I get what he means now.
The rapid changes in your TSH probably account for much of your personality/mood changes. Give it some time to stabilize. Remember for many years you have probably been technically hypothyroid and that feeling became what seems normal to you. You will feel normal on your new dose (as long as it's in the normal range) one day. Couple all that with regular stress and it can be a rollercoaster ride. I upped my thyroid dose in December and about mid-January, I started feeling it. Pretty badly. I finally had to get into my endo this past Friday to get the blood work done. My face is turning red easily, my palms are beet red when I get warm. Then to top it off, after feeling high strung all week, my daughter's apartment at college was broken into and they all had their laptops stolen. I spent most of last weekend gathering the police data, dealing with insurance, trying to purchase her a laptop from 4 hours away. I sure didn't need that but it all feels worse when the thyroid is being messed with.