Hi neptune1980
ESA is an indefinite award with scheduled reassessment based on the Prognosis Date completed by the assessor in their report, as you are in the support group your existing CB ESA award continues in payment until a new Decision is made.
If you were in receipt of CB ESA but in the WRAG group then as you rightly stated your claim would only last one year but as you stated your are in the support group then your claim is indefinite until you are re-assessed.
When you apply for UC, you can still receive CB ESA, this is paid fortnightly, the amount you receive will be deducted £ for £ from your UC applicable amount. You should receive the LCWRA element as you are in the support group.
I would advise you to seek help from your local Welfare Rights Organisation:
advicelocal.uk Gary