That's a very high TRT dose bro, you will need regular bloodwork whatever amount you run. I'm not on TRT myself but I would have thought that test cyp was a better bet than Sustanon.
You may have aggravated the blood vessels at the back of your head, if so it can take a while for your body to adjust back to normal but in the meantime it won't take much to set the throbbing off again even if your bp is reducing.