IPhone :: Suddenly Unable To Use Mail App To Access Gmail Account

Shortly after I got my iPhone 4S, I added my gmail account to the mail app (not the gmail app),so that I could read my email on my phone, and specifically not using the Gmail app, but using the email app, and adding the Gmail account as an Exchange Server so that my Google Contacts would sync to the device. It worked for weeks. Now, suddenly, it says wrong password whenever I try to check my email. I have removed it and added it back. I did not change anything on my email account configuration that would cause this.

Since it happened, though, I have removed the account and re-added it. It seems that it would stop me from adding the account if I were using the wrong password, but it lets me add the account with no problem, and only gives the wrong password message after that, when it tries to begin downloading emails.

I have typed in the password enough times today to make sure that I am typing it in correctly. I have been able to log into my gmail account via the web successfully (proving that I do know my own password). I even downloaded and installed the gmail app and was able to use it to get to my email. But that leaves my phone with zero contacts, because I keep all my contacts in Google Contacts, and the Gmail app doesn't seem to add any contacts to the contacts list on the phone. I need it to work the way it was set up & working before today. I don't know if Apple changed something, if Google changed something, or what. I would think that there would be others using this functionality who may be similarly stuck.

So my question is: How can I access my Gmail account from my iphone and have my google contacts brought into the phone's contact list, and constantly synchronized with Google contacts, like I had going before today? With the addition of iCloud, it gets really confusing really quick. The simple solution that I was using was so nice. I will be sad if it is gone for good...

Info:
iPhone 4S, iOS 5.1