It's possible there is a connection with your low T levels and having headaches.
How was your mood before you started your cycles for these past years? Did you have some zest for life or were you reluctant or complacent? Were you depressed at all or just not a vigorous person be it mentally or physically?
I know the last time I was on testosterone I tapered down the dose and then came off cold with no pct whatsoever and I have to say that for 3 weeks I was listless, lacked drive and my sense of well being was dogshit.
While I did not have headaches my head during this period at times felt quite odd which I attribute to the lack of testosterone my body wasn't producing before it kicked back into gear.
Nowadays I don't think alot of these guys that do pct after a cycle "like they should" have experienced the real effects of coming "off" without pct assistance because the way you feel coming off cold and waiting for your body to kick back into gear and going through a smooth pct is literally like night and day. I literally notice almost nothing during a clean pct which I have done several times. Coming off cold is WAAAAY different.
I could fully believe that the higher levels of testosterone could be causing a cessation in your headaches.
I can't prove this and I don't even know if this is medically documented any where, but I do know low to zero levels of test makes you feel like shit both mentally and physically.