You really ought to retain an attorney for an hour or so to help you sort out your legal situation and to provide some direction and advice.
You should consider filing whatever pleading or motion you deem appropriate as soon as possible and not wait. That way, you can contend that you filed as quickly as possible.
Your question is quite confusing, and difficult to answer intelligibly.
It appears the MSA is irrelevant. Given that it was signed in 2006 and that you just had a default divorce granted in 2013, your initial divorce must have been dismissed or non-suited. Accordingly, do not hang your hat on the MSA.
As for the deadlines, you really need to speak to a local attorney to review your circumstances in more depth.