Milliepede
Not all is lost...
Cotford official address was NortonFizwarren which is slightly nearer, but Somerset Heritage Centre do have the records for cotford, but most files are closed so you will need to provide a death certificate for any information, the files include minutes of meetings, staff, admission, discharges, death's etc. You may have to pay for a search to be done which is if I remember rightly £25 for half an hour. But the staff are very good over there so do have a word with them.
A bit of history on the hospital
Cotford was built in the late 1890's, an asylum it was pretty much self contained and cut off from the outside world, it had it's own chapel, I believe burial ground, even housing for staff. It has gone under two other names, Somerset and Bath mental hospital it's last change of name was in the 60's when it became Tone Vale finally closed it's doors in the mid 90's with the new care in the community.
It has been redeveloped and is now a village called Cotford St Luke, some of the buildings still remain and either been turned into flats or left waiting for redevelopment. So worth doing a google map, and also if you google Tone Vale you get loads of information.
If nothing at NortonFizwarren, then Try either the Taunton, either the main cemetery on Wellington Rd, or St James' which is the nearest Taunton parish on that side.
Hope this helps