How many agents have you queried? One?
If it took you a year to write your first novel, then why wouldn’t you spend at least a year promoting it? The writing industry is extremely saturated, so finding an agent or publisher is all about persistence.
Kim Liao even suggests aiming for 100 rejection letters every year, because being persistent enough to get 100 rejections will also lead you on the path to getting an acceptance.
I haven’t found an agent for my first novel yet, but chipping away at that dream every day (47 rejections and counting!).