Do you know what your blood pressure is? After that episode I got a BP cuff that I use on a regular basis just in case. Either way the headaches are a deal breaker obviously, but still it'd be good to keep an eye on your BP.
I didn't have any problems on 100mg/week with E3.5D injections but everyone has a different threshold.
As far as solutions, I think if you moved to daily injections on your 100mg/week, there's a good chance it would take care of the headaches and elevated BP if that's where they come from.
One thing I didn't try at the time was to stay on E3.5D injections but add a bit of AI to bring down E2, which I personally believe is largely responsible for water retention -> elevated BP.
If you absolutely don't want to touch AI's and daily injections don't work, I personally saw much lower E2 levels on the compounded cream, especially when applied to areas other than the scrotum.
My E2 on 18mg/day of Cyp ran around 60pg/mL with Free T around 25ng/dL. When I got the cream, I got a prescription for 8 clicks/day of the 200mg/mL compounded cream since I expected to need a lot more when not applied to the scrotum.
Not wanting to waste my time if I didn't absorb well, I applied the whole 8 clicks at once on my arms every 24 hours. My free T at trough (after 24 hours) came back at 65ng/dL, but despite that my E2 sensitive was only 40pg/mL, which is kind of crazy but perhaps not that surprising due to DHT's antagonistic action vs E2 and the presence of a high number of 5a-reductase enzymes in the skin; typically transdermals lead to much higher DHT levels.
So you could try that also.
Lastly what I'm trying right now is daily Test Prop subQ, but if fluctuations are your problem, which is likely, Prop is probably going to lead to the same negative side effects. People are often confused thinking that daily Prop must lead to very stable levels since it's injected daily, however daily Prop is actually not any steadier than once/week Cypionate, assuming a half-life of around 5-6 days for Cyp and ~20 hours for Prop.
Daily Prop still leads to quite a lot of variation in levels, which is good in some ways (less desensitization of Dopamine receptors over time probably) and it seems for a lot of people leads to subejctively much better mood/energy/libido, less water retention, etc...but on the downside doesn't prevent negative side effects if you're sensitive to fluctuations.
However if you struggle with feeling flat on Cyp or in general not as sharp mentally or with subpar libido, Prop might be worth a shot. In that case, I would strongly recommend starting subQ, which theoretically should significantly narrow the amplitude between peak and trough levels, and at a low dose around ~10mg/day.
Given what you've said though, I'd look at your E2 levels and either try a small dose of AI (maybe 0.125mg or even 0.0625mg twice/week), or the cream. Personally the cream applied to the scrotum led to insanely high DHT levels which I'm not comfortable running "for life".
Even on just 1 click (50mg) every 12 hours, my trough DHT levels were 360ng/dL (range 12-65), so yeah...brutal.
