I'll preface this by saying I know nothing about racing/pretty much anything to do with cars. I do know a whole lot about job advancement and accomplishing what you want. Stick with your job so that you do not end up in debt - unless of course you're presented with a better opportunity in which you will be more than able to pay off your debt. While you're doing your job, don't place all of your hopes on a company/group picking you up because you've sent them an email. Continue to do this (who knows what'll happen) but the chances of this happening are 1/1000, not to damper your hopes.
Always put yourself in the best situations you can to better your chances of success. As someone mentioned above, go to any and all races in your area and try to meet as many people as possible - don't feel bad explaining your current job and qualifications, somebody somewhere will desire your qualifications. The biggest thing at this juncture is to remember everybody - keep notes if you need to. People are much more responsive/kind if you remember a thing or two about their lives and the conversations you've had with them.
Keep your head down, learn as much as you can, and someday someone will listen to you and see a spark of hope.
Feel free to PM me if you'd like - I've gone through similar struggles in a completely different industry and feel as though I understand human reaction fairly well. I hope all the best.