Dear Mr. S,
Well, your wide skills base suggests that you shouldn't have any problem finding another job, but one possibility that comes to mind would be to re-train as a Design and Technology teacher http://www.tda.gov.uk/recruit.aspx?ilewa=10000437.
On the freelance side, I suggest you put a portfolio of your work together and mail-shot all the small architectural practices in your area. Most will be shedding staff (my neighbour is a young architect, and so I know what is happening), but they still need to work, and so buying in help as and when they need it makes sense as then they don't have to the meet the monthly overheads (salaries, NI, pensions etc). I cannot imagine you not getting work, particularly if you can offer complete confidentiality, something I think many architects would worry about. Signing a confidentiality agreement should sort that out.
There may be a niche market in helping people visualise and plan a new house extension before employing the services of an architect and/or builder. It has been my experience that architects tend to design what 'they' think you should build', and not what was requested at the initial briefing meeting. This leads to delays and extra costs as a compromise is sort.
Just a few thoughts.
Good luck!
Kind regards,
Bob