beginning my journey of DB

[Cadet]

This just feels so strange, like the last 11 years of my life just didn't happen at all??

LBS can rewite history too.
Be careful what is real and what is not.

How can I save our marriage if our contact is zero.....! ?

DB'ing is counterintuitive.
Trust the process.
It takes a long time to get to where your marriage failed and a long time to turn it around.

Is is ok to date whilst Db'ing?

Why are you dating if you want to save your marriage?
Is it for revenge?
Or CONTROL?
Or is it some other reason?
It sounds like another person is going to get hurt if things get serious.
Will it be YOU or the person you are dating?

So, do I continue not to contact him? Do I continue dating?

Yes let him contact YOU.
Dating - Examine your reasons and decide what you are really trying to accomplish.
If you are done with your marriage then - Divorce and Date.
If you are trying to save it, then why are you dating?