/jp/ - Otaku Culture

Hey guys! こんにちはです。
So, I've been learning Japanese (Nihongo) for 3 years now... 1 year self study and 2 years in uni. And i feel like the kanjis are just not sticking with me. What should I try to memorize them for more then a week? I now about 100-120 kanjis already and can read basic material in romanji and a little bit in hiragana.
My current learning method:
Just go to Japanese websites and write down kanjis i see there.
Try to guess the reading without looking up... I don't get it correct most of the time :(
Look up the reading and write it down in romanji, hiragana and katanakana 3-5 times until i remember it.
Beat myself on the mouth after I forget it in 7 days (＞﹏＜)
What can I do to improve my learning? I want to be fluid in Japanese in 5-10 years, is that a reasonable expectation? And is it even possible to read easy mangas by learning yourself (without taking a class)?
Advice would be much appreciated, thanks!
共ありがとうございましたです。
ps: sorry for bad english, it's my 3rd foreign language...