Hamster still scared

[Muffintop4]

Hi all could really do with some solid advice.
I have now had my male Syrian hamster for almost 4 months and these past couple of weeks he will not come out of his burrow if I am in the room. Previously he had been fine being around myself, always going to a certain corner to get treats and even running on his wheel when I was around.
About 2 weeks ago I went to take him out of his cage to give him a check up and he bit me for the first and only time, actually drawing blood. I did not freak or drop him, just gently put him down.
Since then I either dont see him as he is out too late, or he sees me and runs away so quick I dont have time to talk to him.
I'm really stuck with what I should do as he is my first ever hammy. Please can someone help?