I also didn't gain much head size in over a year of Penis Enlargement, although I made good gains in length and girth.
I finally started making some good head size gains when I kegeled before/during a slow/hard jelq . My head actually hurts when doing this and I don't do too many. Also, I don't jelq al the way to the head, reasoning that I don't want the majority of blood escaping past my hand. I start the next hand before the previous has released. It's hard work and I can even break a sweat doing this.
Another advanced technique is doing a wrap which is something BIB taught me although it takes some time to master.
I would add though that your head would probably grow some regardless as long as you are making gains on girth. It just seems to take longer.
Do slow long jelqs . I have a big head and it keeps in proportion to my midshaft even when i gain on my midshaft girth. I think it's as i jelq at high erections percents. I know you're not meant to but i can't jelq and not get hard, so i have to jelq at high percents. My head gets big when i do it though.
Either do slow long jelqs at 60% or quick jelqs at 90%. Don't do slow jelqs at 90%, you'll cause an injury.