I am holding on a q2 visa in china n im already married with my chinese gf.

Atif, I guess you have a single-entry Q2 type, right? If so, you need to apply another Q2 type when you return to mainland China. According to the rule, you need to get back to your country to apply for another Q2 type if you don't have resident status in HK. However, many foreigners actually applied their visas via agencies in HK successfully. You may try to find some agencies and ask them to help you apply for another Q2 type if you don't want to get back to your country.