@Marissa-F
The PM self-serve My Account website was down for most of Thursday due to a system outage. Unfortunately, the website appears to be undergoing more maintenance work at the moment, which is why you can’t sign in.
The problem is on PM’s end, not on your end. There’s no need to change the password in your situation when it is a system error. That will not restore access to your account.
Please try accessing the website later in the day when the maintenance work is over, and sign in with the new password that you changed to.