I am an avid squash player however I have a problem. I keep on
breaking my strings!  have broken three sets in the last month alone.
I think it is because of my style of playing, I started off playing
badminton and as a result I use my wrist a lot. It could also be
because i slice the ball too much. Is there any literature or
knowledge out there (other than personal opinion) that would match an
illness to the symptoms?? I play at county-level.

There are really only four reasons why your rackets would be breaking
so often. It doesn't have much to do with you using a lot of spin.
1) Your strings might be strung too tightly. Often, stringers used to
tennis string squash racquets too tightly. In that case they would
break too often.
2) Your rackets may be strung with too-thin strings.  Highest quality,
thinner gauge strings are used by professionals to get maximum spin in
competition, however this is a marginal advantage and does result in
more breakage.
3) (Most likely) your racquet might have a flaw in the stringing holes
which is causing abrasion with the string and resulting in breakage.
The stringer should be checking for this.
4) Very hard hitting and a lot of spin imparted can result in more
breakage, but shouldn't be resulting in the frequency you are talking
about.

I hope this helps!

It is easy to see where the string breaks, and also to recognize wear
from slicing.  The latter wears flat the strings where they cross,
rubbing against each other, eventually to the point that one breaks in
the middle of the racquet.
I wouldn't consider slicing too much to be something you want to
change, if you are successful.