I wanna start off by saying you have very good mechanics. Great weight transfer, good balance, very nice to see.
What lost you the fight was head hunting and letting him control the range. He was a guy with a lot of head movement and level changes. Against someone like that, swinging only at the head is making your life much harder. Jab his chest, jab his stomach, punch his shoulders and chest, try to knock him off balance, create openings or hold him in place just to find him so you can land clean punches. He wasn't picky about whether he hit you in the body or head, so he landed more effectively. Even though you moved your head well, he was still able to find you a little more than you found him.
Beyond that, you had to commit to moving forward every time you engaged. That meant all he had to do was wait for your attacks, slip or duck under them and start going to work. He was often able to get his head on your chest and smother you afterwards to take away your counters. What you needed was to feint your movements. Step in the step back. Step in once then stop. Step in, then circle out. Make him guess when you're actually gonna be there to get hit. If he comes in like he was when you were taking a careful step out, you'll be able to see where his head is going and hit him. Feinting in general would have gone a long way. Try to trick him into biting with his head movement then counter him. For example, you might have been able to land some uppercuts if you got him reaching to land his body shots.
I do think you looked good out there. I'd love to watch you in an MMA fight, because I saw some pretty damn good boxing in there! It was a close fight and you put on a good show. Thanks for sharing and respect for posting a loss!
