Can i go to japan with my criminal conviction

Its been my all time dream to go to japan since i was young but sadly my life took a different turn at one point and served a prison term of 2 1/2 years for possession for the purpose of export of methamphetamine at the age of 18

i am now 22 years old and wondering if its even worth trying

If you did jail time. You will not be entering Japan.

you can't enter Japan FOREVER, because of DRUG criminal.
Immigration Control and Refugee Recognition Act, Article 5,
(v) A person who has been convicted of a violation of any law or regulation of Japan or of any other country relating to the control of narcotics, marijuana, opium, stimulants or psychotropic substances, and has been sentenced to a penalty.

If you have some sort of proof you've reformed and character references from say an official of some sort, and then go to the embassy in person and explain the situation....maybe.
However, I do recall they wouldn't let Mick Jagger in at one stage because of his past.
Good luck.

You have Zero chance. Any other conviction you might have had a chance after say 10 years or so, but being a drug conviction gives you no hope worse still a conviction for drugs on an export scale! You can pretty much forget about travelling to just about anywhere.

'You can't travel anywhere' is not entirely true. I'd say that Japan is out of the question, but as long as you are upfront (which by the sounds of it you are), some countries are not so strict.
The Japanese authorities will stick to rules no matter what, even for the littlest thing, and even when you would think common sense would prevail. They will not budge.

It's one of those things - if only you could go back in time and talk to your younger self...

Good luck mate.