I have done PGDBM, so can I do directly MBA? Because I have not yet pursued any degree but have experience of 7 years.

Actually, PGDBM = MBA, different institutes give different names to the MBA degree. So you do t need to worry PGDBM is equivalent to MBA. Most of the universities give MBA degree, IIMs and autonomous colleges gives PGDM degree, XLRI gives PGDBM degree but all comes under the umbrella of MBA.

No, you need atleast a Bachelor degree to pursue MBA. One option can be to pursue graduation through distance or regular mode.