In your situation, you really cannot use any title, except perhaps, the generic "Consultant."
For example, I have most of what you have and then some (basically almost double the years); however, the only certification(s) I have are for my primary which is in Chemistry, and even then I rarely use them as they are not PhD thus come across as somewhat, well, self-important unless they are needed to certify to Government agency or a customer requests certifications.
You can look into certification programs that might be offered by a local university (call them, they can usually direct you to the right sources) or something like what is offered by Microsoft:
Microsoft Office Specialist (MOS)
BE VERY CAREFUL with any of the internet offers, there are a lot of valid programs out there; however, there are a lot of roaches wating for the unsuspecting victim!
(also, I'm moving this to the career advice forum.)