There's a lot of good advice in this thread, and I've read your responses to many of them. I want to bring up the possibility that your feeling of impending doo

There's a lot of good advice in this thread, and I've read your responses to many of them. I want to bring up the possibility that your feeling of impending doom in your professional capacity is actually more a reflection of the significant personal and financial stresses that you've been going through, rather than due to any real inadequacies in your engineering ability. If you've been able to lead a team for half a decade successfully, then you would definitely count as a capable senior engineer. From one of your other replies, it sounds like you've stopped reading professional books. That's completely understandable due to what had been going on with your father (RIP, condolences). So before you do anything rash career-wise, I would advise you to take a break, get your own mental and physical state back to a more healthy state, and then see if you're still having the same panicky thoughts regarding your career.