Is it ok to have some drinks when i go out after falling on my back a week ago? it still hurts, but i also want to enjoy myself with my friends.

Use moderation: Alcohol can significantly reduce pain. The problem is that if you have more than a couple drinks you might not be attuned to the pain and, in this case, the pain is there to tell you which motions and positions might further hurt your back, so I would not drink too much to avoid hurting your back further. And, of course, do not drink and drive.