MelonPunch, I've been reading this thread for a while but only just now got curious enough to plot out what you did to try to see why your PCT might have failed.
In the charts below I assume 600 Test E and 400 Deca/wk with a shot frequency of 2x/wk. 10 days half life E 14 days D.
View attachment 567639
In this plot I used last shot Deca start of week 5, last shot TE start of week 7. I'm making an assumption that when you said you waited two weeks to start PCT that this means 14 days, so all the number I'll throw out are based on that. If what you really meant was start of the week 11.5 days later than last shot then the figures would be slightly higher (i.e. worse in terms of bleeding down).
So, start of week 9 your combined Test + Deca is still 50 on this chart. Contrast that 50 to "normal" Test production of 10mg/d (which is equivalent to 70mg base/wk or 100 mg Test E/wk) which gives a level of about 14. So I usually recommend waiting to start PCT until your blood levels bleed down to this "normal" level of 14-ish. That does two things - it keeps your hormones high enough (i.e. higher than "normal") before you start so your shouldn't lose much mass, and it starts low enough that your body has a chance to start seeing a signal to restart. To hit that 14-ish you should have waited +5 weeks after last shot. That's what happens with long esters like E and Deca, they take forever to clear out.
So starting PCT +2 wks after last Test E your level was 50, at +3 wks 32, +4 wks 20.8, +5 wks would have been 13.5 - still pretty much 100% suppressed, but this would have been where to start.
At +6 wks after last shot you wrapped up PCT. At this point blood levels are 8.8 which compared to "normal" test production is still over 50% suppressed. Since you said your test is naturally pretty low then for you you might have still been 100% suppressed.
Add all that above to Deca's potential in some people to lead to ED, and you just might have a recipe for what happened to you. Best thing I could suggest is to give it time now. The Deca in your body will literally take several more months to clear out, including metabolites. If you wanted you could repeat a course of low dose clomid and nolva to try to kick start things, but according to you the test result you got of 370 is about normal for you. If that's so, the only thing a bit out of whack looks to be low FSH. So more clomid and nolva may not help, but probably won't hurt either.
I think you just need a lot more time, like several months, and you probably want to think about not doing Deca or NPP ever again.