5’11 vs 6’4

Hi, I did Muay Thai for 3 months a year ago and I started again 2 months ago, 6 hours a week, and I do MMA on the side. I’m doing pretty well. I have a defense that I find pretty solid. I block well, keep solid, and I dodge pretty regularly. I box a little outboxing (I don’t know the term here). I box mainly with the left with low kicks, and I dodge and counter. Everything is going well, but I have a lot of complications with taller fighters who have a greater reach and who dominate the distance. Do you have any advice on how to progress against them?