I needed to change my gmail password and now have issues getting mail on my iPhone 4S. The message is "Cannot Get Mail The user name or password for "Gmail" is incorrect." I did not have an issue on my iPad or computer. Advice?

I needed to change my gmail password and now I cannot get my iPhone 4S to get my email. The message reads, "Cannot get Mail The user name or password for "Gmail" is incorrect." I have verified this account several times, I have deleted and added my mail back in and I have done the two-step verification several times. In addition, I have shut down and restarted my phone several times. Shy of heading to the Apple Store for help, does anyone have any other suggestions for me? After a week of working on this, I am at a loss!