My personal experience - and it's hard to say if it would apply to you- but nonetheless - was similar. I felt like I was dying on T4. Actually, I joked I'd have killed myself had I had the energy to figure out how. I had no energy, and just felt so bad. My doctors prescribed antidepressants! It was so frustrating because I wouldn't take them, I wasn't depressed. Finally I met my current amazing doctor who put me on t3 and changed my life. Conventional doctors say my dose will kill me, but I feel GREAT. So..I don't think they were any better by insisting I stay on t4 (which made my TSH 'normal' but made me feel terrible).
My not-a-doctor recommendation is get some t3, and start on 5mg for a few weeks and if you feel better there's your answer. Increase to 10 (5x2 a day). If jittery decrease. If not stay there. You should decrease levo if on t3. Others may be better suited to tell you how much, I would decrease to 100 or LESS - and even less as you increase t3. I'm not a doctor so I'm not qualified to be writing this -this is just my experience. I'm now on ZERO mcg t4 and 100 mcg t3. I don't convert t4 so being on t4 only was useless for me. That's just my non professional advice!