You seem to be casting around for something new but without a plan. Draw up a balance sheet of what it is you like about teaching and what you hate.
Have you stopped enjoying your subject, or is it that you no longer want to teach lots of groups and work with a smaller group that you can get to know better?
Retraining is problematic, with virtually no formal schemes. Your qualifed teacher status still allows you to teach anything to anybody within the school system. Consult someone from the local authority advisory team or the professional development centre, if there is one locally, to discuss options.