I assume the extra courses would have to be at an ABET accredited school. The Board rule I posted is from Texas. Not sure about other states.
You can always try to apply in another state. worst they can say is no.
Take some college courses quick!
If you did not pass the PE exam within the three allotted opportunities, you will need to re-apply to take the exams. You must gain at least one year of additional engineering experience from the time you are notified of failure to pass the third exam, or...
Not to sound rude, but you should have a left your company 10 years ago. Also, If you are working in Building systems/MEP then you should not have waited 15 years to get your PE. MEP is all about the PE!
Keep looking and be persistent. Make your LinkedIn profile pop out to recruiters. I was not...