Lost my Libido

Take a break from fapping.
Exercise to improve blood circulation.
Try out cuisines with aphrodisiac effects like eels, mussels, cows testicle, etc.
Korean Ginseng.

lol same case as me
Take a break from hentai world, do a workout and make more muscle.

I don't know about other girls, but for me the pill sometimes just kills my libido for weeks. Then I'll be a nympho for a month or two, so maybe it's just hormones? I'm sure guys have them too.

( sigh ) ...

First things first ... you gotta accept the fact that Hentai will not last in your life, and that it will never satisfy you the way it is meant to be. try and get social and get to know a few people and maybe girls will come along the way, if you already know some girls then just politely ask them for a date and then ask them for sex, in some weird cases girls will accept that since they too, are longing for it, since it's normal to have desires for it.

I feel sorry for you if you fapped to thousands of doujins and it doesn't give you that kick anymore, you maxed out man, time for a new chapter,

Hire a big-butt hooker and grind the "little you" on her butt.
Works 99% of the time.

Just don't fap for a week. That 8th day will be great, trust me.

as someone who has gone though something similar i can say that the way i got though it is that i would use the power of my imagination to expand on some of my favorite fetishes or doujins and create a fap worthy scenario

I found this method to be simple and effective

I used to fap to vanilla doujins all the time. It's what I got off to. Then I wasn't able to fap to vanilla doujins anymore. I thought I just wasn't able to get off to hentai anymore. Turns out that wasn't the case, I looked in other 'sections' of hentai from futa to incest to other stuff and I was able to get off again. Try different stuff.

"Variety is the spice of life and sex drive."

Switch between different porn / hentai media every now and then. Today, watch porn. Tomorrow, play some hentai flash games etc.

If it still does not work, take a break.

Take a break. You are getting used to it. Just like how what got you hard as a kid most likely doesn't now.

You've heard the "stop for a while" argument, but if that hasn't worked out for you by now, try that doctor bit. There are a myriad of silly reasons like mild depression, sleep deprivation, or even something as silly as not eating enough fruits and veggies (aka mild malnutrition) that could mean your body is putting something dumb above your need to procreate. It sounds silly, but the human body is a finicky douche, and any one of these along side a great deal more could be causing this sexual rut, though you should check with a doctor, because it's probably something you yourself wouldn't guess/recognize.

I've never fap'd to hentai mangas so...cant help you lol

They are great foreplay though when you've got a girlfriend who enjoys them...

Yes what you're thinking has probably happened

Drink some caffeine, it will reinvigorate yourself.

Happens to all of us. Take a break. Have a kit-kat.

Take a break of heantai, rest better (sleep), eat healthy and do some exercise (it helps a lot).