I did this combo. I had horrible side effects and was advised that they were all RT3 related. Ultimately, I've since returned to a synthetic med after a nice run on NDT and NDT/T4.
I'm on naturethroid and I wasn't right until my labs, frees were much higher than yours. My FT4 is 1.4 and my FT3 is 3.8 (same ranges as your labs)
I knew before my labs came in, I felt so much better...I can't answer why you aren't just increasing your naturethroid, I ended up at 2.25 grain but it's very individual and body weight is a factor etc. according to my NP.
From your anxiety and labs it looks like you need more medicine. We are all unique, but I am doing well on a combo of levothyroxine (112mcg) and Armour (2 grains).