What does the tiller feel like when you attempt to go close hauled? If there is adverse pressure (excess 'weather helm') on the tiller/rudder you will not be able to 'point'.
There are many conditions that will cause excess weather or lee helm
1. loose rigging, below correct tensions
2. sheeting the mainsail too close or 'above' the centerline towards the weather side
3. For pointing in 10-15kts. the aft end of second from the top batten should be somewhat parallel to the boats centerline.
4. A dacron mainsail with 'boltrope' if not correctly raised and then additionally tensioned by the halyard tension will be very full draft, draft aft and with the leech 'cupped up' toward windward = weather helm and dragging rudder - see below.
5. a too loose headstay, one that is sagging off to leeward will cause the boat to 'skid' to leeward and will prevent 'pointing'.
6. get and apply a full set of tell tales for your sails - behind the luff, at mid-cord, and at the leeches .... its IMPOSSIBLE to have good trim and sail shape without them.
How raise a 'boltroped' dacron mainsail: How to properly RAISE a woven dacron mainsail - SailboatOwners.com
How to adjust for correct headstay tension: http://www.ftp.tognews.com/GoogleFil...f%20Hollow.pdf