You're dead on about overspecialization... could that be a reason to forget the PhD? Holistic science doesn't fit very well in academia. Hmmm, there's a book that might speak to you, The Independent Scholar's Handbook (it's online somewhere). I like the chapter about Alvin Toffler working some lame reporter job in D.C., struggling to achieve recognition, writing Future Shock in his spare time... and the rest is history!

Anyway, things will probably work out fine if you ignore all the advice you're getting and do what you really want

Best of luck to you and Alaric... hopefully things will turn around soon!

Ella its not just the sitting down its the typing - if I type for too long standing or sitting I loose the use of my hands - I have to be careful when doing anything with my hands especially during a flare up but even just in general.

Actually, I think that science is getting more and more specialised which is a bad thing. There are generalists (or bridges) but to be a generalist in science is much harder. I've been looking for post doc positions and when all the adverts are so specific about what they want, it's hard to move areas.

Regarding science writing, I think that the new scientist runs an essay competition every year to find new writers, you might enjoy doing that.

Regarding your back/health and family issues, I think it's sensible to take things a little slower. It's not giving up, but chipping away at what you want a bit at a time.

Regarding doing a PhD, I don't know whether you would enjoy one or not. Yes, they are very focuses. To begin with you can learn a little around your subject (but not much as you have deadlines and things to focus on), but you do end up going very deeply into a small part of your subject. This will teach you how to do research in a way that a several short term projects on different subjects won't, because you see how the direction changes over the time of research.

Regarding sitting down using a computer, I've started standing up using my laptop. It means I move around a lot more and change position a lot (and well as doing yoga style standing on one leg poses as I think). When I had to spend an entire day sitting at a computer I found I got really fidgetty! Anyway, clearing a space on a dresser so you could sometimes stand up and type might help with you back, perhaps.

It's not a bad idea to get the Diploma: it'll give you something for your effort and allow you to get closure on that part without breaking yourself for the MRes or abandoning it altogether. It's similar to what Kiki did. She switched to the PGDip from the MSc because she decided that she'd done the bits she was interested in and was ready to explore her plans for something new.

Don't let the PhD be something that you promise yourself and then spend all your time waiting for it: that'll just depress you again in the long run. I've always been interested in doing one but, when I left college I decided that I was done with academia and it was time for something different. I decided to reevaluate the PhD thing when I retire... Yes: that's a long way off. But at least then I'll know that I'm doing it because I really want to rather than because I think I need to for whatever reason. I've not even committed to doing one then: just deferred the decision until then because I know that I've got a whole truck load of things that I want to do now; and they're going to take a long time.

Carina's comment about choosing art or science and keeping the other as a hobby is a really good idea but it does take discipline, especially if you are naturally a dilettante. Don't plan to do too much: just take one, or maybe two, projects in hand and completely ignore the rest until you've worked out how long things seem to be taking you. If you plan more than that then when things take longer than expected (which they always do) then you'll just end up feeling under pressure and depressed that you aren't keeping up.

Sure, make a big list of projects that interest you, but once you've picked one, plan to only finish that one and make sure you break it down into small, achievable goals: things that take no more than a couple of hours, or maybe an afternoon, to accomplish. That way you'll have plenty of time left over to do the things that really must be done, you'll feel like you have done something you wanted to do and you won't feel like you are falling short.

Good luck. It's very difficult to decide how you want your life to be and then to shape things so that they turn out how you wanted. Many people don't know what they want or even try to work it out: just look at the number of people that join a random company and stay there, plugging away for years and years. I guess some get lucky and find something that they like first time, but I bet most of them do it just because they don't know what else to do or don't want to take charge of their own destiny.