You will need to show that you signed under duress or there was fraud involved or that your attorney attorney was negligent or that an error/mistake was committed. You have up to 6 months to file a motion under CCP 473. After that you will need to show deep prejudice to you based on the above. I suggest that you need to seek legal assistance on this. You really haven't presented any facts that would cause a court to set it aside. Unless you can prove that your attorney committed malpractice or was negligent, you will have a tough row to hoe.
"I wanted a more aggressive lawyer" isn't enough of a basis to get a judgment set aide, by itself. The court will assume that you're a competent adult, and that you picked your own lawyer, and then you agreed to a settlement. If you had adequate information, and nobody coerced you improperly, the court will not usually simply let you "un-make" a deal you made.
You may want to review the facts and agreement, and the facts, with another attorney, to see if there's any other basis for a set-aside.
I agree with counsel and recommend contacting an experienced divorce attorney to determine if there are any facts that might support setting aside the agreement. Good luck.
The court is not likely to support "buyer's remorse." If you signed the MSA, with counsel, getting "the best outcome" is not likely a good enough reason to set aside the MSA, even if you were within the 6 month period to do so. You've also indicated you will receive support for 10 years; that's a long time. There's no guarantee that spousal support would have continued even if there was no termination date because you would have been likely given a "Gavron warning" to become self-supporting within a reasonable time.
Best of luck,
-Sanjay A. Paul
This is not legal advice. No attorney client relationship exists between us.