Nice to hear from you again.
It's true that you can get health insurance by AOK after 15 months of staying in Germany. Before this deadline you get a so-called "Behandlungsschein" by Sozialamt that you can use to go to the doctor.
I'm not entirely sure what you mean by "social code x2".
Regarding your housing situation: Unfortunately we can't do much except telling you which websites you can use in order to find an apartment and what's the best way to proceed. Please check out the following thread here on Wefugees:
Also, this thread about Wohnberechtigungsschein (WBS) might be of interest for you: