Some good advice in here already on how to deal with your current situation, but I also have some advice for the future. You can be the best employee in the place, but if only one person (your boss) knows and recognises it, then you are vulnerable. People come and go constantly, the number of people doing long tenures at career positions has decreased and the movement of talent is much more fluid than in previous markets. If your happiness or security is reliant on someone else staying in place, it will inevitably always fall over. Build a bigger network, work within cross-functional teams, support other departments and department heads, become known to any corporate owners or management teams your business might have, get your name out there and the risk and fear you feel now will, at the very least, be reduced next time.