Can't Log Onto Tumblr

I wouldn't be making this if I hadn't already tried logging in so so many times...

My phone browser can't have two windows open at the same time, and it's really annoying. So it logged me out somehow and now I can't log on. It makes me start to sign up for a Yahoo account. I don't want a Yahoo account I just want to get my Tumblr back up. So since I can't get two windows open it makes it so much more difficult to do anything...

Please tell me there's some way I can fix this....