I had a similar past, and in fact left a stable drafting job when I realized that I was never going to be permitted to do any true engineering work. But, then I still didn't find any engineering work for many years. I ended up with the job at I have now because it was a long-time friend I had done drafting for early in my career. It is a 5-man company, and he is paying me at least 1/3 less than what I might be able to earn doing some of the advanced drafting work I have done in the past. And, even now, at least 75% of my work is drafting. But, that remaining 25% of my work doing engineering and research is extremely satisfying. Eventually, I may need to leave my current job if he is not able to pay me more, but then I will be able to add the word "engineer" to my resume.
The reason I stick with the lower pay, is that I have realized that I am an engineer, and cannot really be happy ignoring the gifts God gave me. It is not unusual for a job to not be where our talents lay, and you stick with it because you must pay your bills. So in that situation, it is is important to use your creative engineering talents somewhere outside of work. E.g. a robotics hobby. But, at some point, it is certainly worth doing more job hunting to find work that will use your education.
I will also mention another issue. Since I had so many years of work, that did not involve engineering after my eduction, that engineering knowledge started to fade. When I look over my notebooks, and see all the types of problems I really can not do now, I am disappointed. And even now, I feel very much on my own, and would have much preferred to have worked for several years as a junior engineer, with someone to go to with questions. So, that is another factor to weight.
Sometimes we just accept the situation as it is, because of other priorities. I have not pursued jobs in other cities, because I really like where I am now. You may have a family that takes priority, and that is a good choice. Most of the people I have worked for, had degrees in other areas. Though they were often somewhat related. I suppose they had to follow the opportunities as they presented themselves.
There is also a type of inertia that can set in once you get into a job. While you do need to show some stability to future employers, if you have been at your current job for several years, and don't see prospects for a good future there, you need to keep looking and networking for your future job. It may also help to discuss this with your current employer, and come up with a plan for you to start doing more engineering. But, most of the advice I have come across, say that you normally need to change companies to advance.
-Joe