If you were able to retrain in the same industry on different jobs 3 times, learnt web development, you are reading HN / are tech literate and are aware of the

If you were able to retrain in the same industry on different jobs 3 times, learnt web development, you are reading HN / are tech literate and are aware of the coming changes in the industry such as Deep Learning : don't worry. You're on top of the rest of workers in this industry. You will eventually find your new niche skills, and even if you don't, being on top of your current field you have a few years runaway ;)