Is it possible in c++ for 2 DLLs including eachother, because each of them uses eachother's classes(Well that's my plan), is this possible or not?
Yes, this is possible. Only you need to compile these dlls as a multi step process. To link a dll, you need a lib file from other dll. This means that you need:
Also note that DLLs in general have C interface. You can export classes, but be ready to have set of dlls for each version of used compiler.