hassled mum
If you don't know how many points you scored at the last assessment, you can request your medical report from the DWP, by phone or letter.
The 12 month rule for ESA(CB) is not yet law, and even when it is passed, will not come into effect until April 2012, so you have at least 11 months on ESA(CB) before you (and everyone else) needs to worry.
I would wait until you have the medical report, before making any further decisions. Having your existing claim removed is much more likely if you have only scored 15 points, rather than 30, and if you have a genuine belief that you would qualify for the Support Group, you should certainly consider claiming.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems