I can't access Facebook

We were recently traveling and my android had been working fine. The last day of our vacation I tried to log in to Facebook and I couldn't get in as the screen stated I had to log in with my password. When I did, it said it wasn't recognizing it on that account. I did everything the "Need Help" link told me without success. We even turned the android off and re-booted and it still doesn't work. Everything else seems to be working on it. I can access and do e-mails etc. but still no Facebook.

I can access Facebook on my Google Chrome tablet just fine. Can someone please walk me through steps I need to do to regain my access? I'm technically challenged so it will have to be concise. Thank you.