Thanks for the updated information, it seems correct in assuming that you might be training a bit too much, mileage wise. You sound like a super dedicated runner who can do better by doing less. Many years ago I trained a few females in your age category that topped out at 30 miles a week and were able to run under 3:30 for the marathon (NYC Marathon). One ran 3:06 on that mileage (back in the mid 1970's). I also coached a young woman who did 40 miles a week and sometimes up to 50 a week and every indication was she could run sub 3:30, yet would go no faster than 3:45. She was quite intense and a bit anxious, despite efforts to calm her down.
I think the key is to gradually build self confidence by staying within yourself, not over doing the training (which seems to me to be a reflection of self doubt, but I am not a psychologist....ha,ha). You are putting in a lot of hours training, but I think you can get a better return on your time by cutting back on those long, slow miles. As some others mentioned, it would help to work on your shorter distances, bringing those times down and enjoying that aspect of racing. The shorter distances take less out of you and you don't need to put in 18 weeks of long, tedious running (save that for when you are retired :-) ). Your longer runs should be cut back, as I suggested, where perhaps more 11 mile runs at a bit faster pace (closer to marathon pace or even a bit faster) would be of benefit. Your recovery runs should also be a bit faster, probably under 9 min pace for most of the runs.
I am only guessing as I don't know what kind of times you can do for the shorter distances such as the 10k and 5k.
There is an old book I co-authored that you can get on the cheap and I think it will help you. It was written in the early 1980's at a time when distance running by the general public became popular (You can probably find it on Ebay or some other internet source, with postage costing more than the book..). The book is called "The Competitive Runner's Handbook" by Bob Glover and Pete Schuder or the second edition "The New Competitive Runner's Handbook". It was published by Penguin. The third edition was written only by Bob and his wife, so I had no input there.
I am Pete and wrote up the workout schedules for the first two editions, as I did that while head coach at Columbia Univ. I tried to write the workouts with an eye on adults living a busy life, working, maybe having kids and just trying to enjoy competing better. Bob and I used to run the NY City Road Runner's weekly workouts in Central Park where we had 300+ runners each week and many of my workouts were used there.
Check that old book out and see if you can find a category (I am guessing Intermediate) that fits you in terms of your fitness level. The book is old, as am I now, but I think the basics and principles still apply.
Best of luck and I hope your running will improve in the future.