Can I recover a deleted timeline after the project has already been closed?

I was finished with my recent project and clicked open new under file tab. I opened a new project and renamed it to something else. However, the sequence from previous project was still in timeline of new project.. so I deleted it. When I reopened the original project the sequence was deleted from it too! I have already exported that project, so I at least have a copy of it, but had planned on tweaking some things down the road...and now its gone. Help!