That is really odd.. I've noticed today that when I log in, it takes forever to load once I click play, and it almost freezes for 15-20 seconds before it resumes and lets me play. Kind of odd, and this only started happening today.
Do you have the latest version of Java? Also - are you connecting to the game via your browser or the RS client? Those could possibly be factors. Like somebody suggested already, I would clean your computer, empty your cache and delete your cookies before you try again. Good luck!
If you are still having no luck then I would suggest posting on the RS forums. There seems to be alot of people having similar problems and people are working to help get the issues solved.