I love this thread! It just goes to show how much more there is to each of us than just the 'mum' stuff.
Pruni - like another poster said, it took me ages before I refound my interests again after children. A) they were just too young and demanding, and b) I was working full time. Although I still had an interest in things, I couldn't string more than two words together to have a full blown conversation about them (my few brain cells being used up trying to hold my job down!). Having been ill, stopped work, children growing up (now 8 and 10), I am sooooo loving getting back into it all. There is hope, it will come back.
I would say that if you can try and just squeeze half an hour a couple of times a week for your cello, you will feel like a new you! I know that when I don't have time to paint I get very despondent. The minute I've picked up a pencil and whacked the opera on very loudly, then the endorphins start rushing around and I feel on top of the world! Try it (it's better than any pharmaceuticals, and I've tried a few!!)