As a disclaimer I have never received a rejection slip because I have never used traditional publishers. As an Indie publisher I have the ultimate power or authority and I can exercise that authority over when my book is published. I may change my mind, but if I want it published it gets published.
Discover your genre or genres, learn their characteristics, and search for agents in that genre. No matter what, I think you should consider it. But you should explore the world of agents. You might find one you like.
You’ve probably heard the phrase “Everyone has a story” sometime in your lifetime. I believe this is true. Most people don’t realize it, aren’t interested in writing, or don’t know how. But all of us have life experiences that can be instructive or entertaining to the rest of us.
The agent has given you his advice and has made it clear that unless you change things as he has described, he won’t represent you. Complicating the matter is the fact that you have not been able to find another agent. What do you do?