Agmatine in 500 mg doses did not seem to produce any noticeable effect for me.
Any AMPA agonists you know of among things you tried that did help you?
The closest to agmatine I tried was sarcosine and it was nice but had side effects I believe are from NMDA agonism - so different profile which muddies the whole thing. Aniracetam helps in unexpected ways but it's subtle and also multiple mechanisms. (then again Agmatine also has other effects like NOS inhibition)
I'd love to try ketamine, but it's not going to happen where I am. I've tried DXM, it's potent, fits the profile (AMPA+/NMDA-) and it can probably substitute for Ketamine, but I'm not taking those products chronically unless I could get pure freebase or HCl legally.