Can't access Gmail it's constantly "syncing"

[MauiGirl78]

I was sending pictures from my Samsung Galaxy S4 in multiple emails. I went to check if they had been sent after a client did not receive anything, and I found them all in my outbox with a red "sending" next to them. 5 minutes later they were all still there, and I hit refresh to see if that helps send them. No luck, now the sync button will not stop spinning and I can't access my gmail. I did everything the Samsung help on my phone told me to do, Sync and un Sync, check for connection, restart phone (which I've done 5 times now- it's been over 2 hours)...
I have a flight tomorrow morning and need to get into my emails. I've been reading that some people cleared the gmail "data" and it did a re sync? I can't find that option anywhere in settings on my phone..

Please help
Thanks!

 

[Javier P]

To clear data or stop the app go to settings > apps > Gmail.