Are there any scratches on your lens? Take it all the way apart (remove the lens) and look inside the other side as well. I'm thinking you have a huge scratch on your lens that is causing the focus to mess up.
then it's not screwed in all the way. Unless it's a glass assembly and those won't go down flush. However the plastic lens assemblies will go totally flush and down into the chamber. Might wanna pull everything apart and clean those threads out of debris that might be preventing you from going down any further.
As the lens is turned, the laser becomes focused, but after it has become as focused as it can become, it starts becoming unfocused again. Try turning the lens out little by little and the laser should become smaller.