What on earth can I do?

[spababe]

Had some good jobs before children mainly IT project management. Also had my own business for a while organising social events. I have a BSc and a MBA.
However I haven't worked for 14 years and not worked for anyone else for 17 years.
DCs both at secondary and can let themselves in. DH semi-retired and works 2 days a week.
I am over 50 as well which I guess counts against me and also I am fat (although working on this) so will be perceived in a certain way.
I live in a tourist area but not an area with much industry.
What can I do part time that will be interesting but not stressful?? Will anyone be interested in employing me??
I feel that I will be perceived in the same group of things to offer as a school leaver without the youthfullness and energy.

Volunteer in anything to get back into swing of working day/office life
Volunteer for National Trust perhaps if there's one nearby or gardening (sometimes historic properties love volunteer gardeners and they are mostly your age or older!(I'm nearly 50btw and love gardening)
Wedding organiser?
OU for further qualifications to get into a new role.
private tutor for Maths, science or business, primary up
lecturer in 6th form college for business studies?
train as dyslexia tutor
estate agent
holiday cottage lettings organising
set up garden in a local primary, to be handed over in due course when finished
IT product design
Foundation course in Art

these are just some of the things my 50 plus friends do paid and unpaid

I'm a SAHM and not as well qualified as you, so you have a lot to offer.

I also come across countless glamorous professionals who are "fat"/overweight and I don't think it counts against them. Self perception is everything rather than your actual weight.

Thank you for your ideas. I appreciated the reply. I'm not a gardener ! but have applied for 2 p/t admin jobs and have 2 interviews