I had all the same problems. Found out I had a very rare Bladder Infection. Apparently this kind can stay lo and undetectable on and off kinda Bacterial Virus. After a few weeks of Meds, it started to come back to life out of nowhere again lmao.
No biggest thing I notice is it is a Male Heat thing. For First week of the Month roughly. I get Really Fucking Horny! Then nothing for a few Days.
Then I read on Playing with it too much, De-Sensitizes it! So once before Bed, if it doesn't work, Then relax sleep. Wake up Hard and GO FOR IT LMAO! What i do lol.