Praying is never a waste of time. But you have to work along WITH your prayers to show God that you are doing everything possible. Hoping is never a waste of time either, but ask friends for feedback, then maybe change your strategy.
If you have been praying for a solution for quite some time, and you don't feel like you are getting an answer, maybe try changing the prayer. Instead of asking Him for a solution, ask Him to help you cope with any outcome, regardless of the results.
This is what I do. My prayers are ALWAYS heard, I know because, they are always answered. I don't always LIKE the answer, and when I don't, I ask for help to cope with the answer I am given.
Hope this helps.