As you scored 18 points you will have been placed in the WRAG, your appeal is to be placed in the Support Group, the Descriptors for the SG are not points based, you need to meet one of the SG Descriptors to be placed in the group.
If you have a look at the ESA Claim guides then the routes into the Support Group are listed on page 18 onwards of the Physical guide and page 20 onwards of the Mental Health guide.
Both the Controlling your bowels and Coping with Social Situations offer routes into the SG if you can show that you meet the criteria. The Going Out activity cannot lead to a SG award.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems