hi,
as stated elsewhere i have never travelled with shearings to lloret, but have used most of the other companies.
for specifics on shearings have a look here
re insulin, i would contact shearings direct, their number is in the above link.
i assume you are on the express coach, ie no hotel stop in france on the way down, and if so, almost anything you read on here about ferris or siesta coach journeys will apply to your journey.
most coaches these days are comfortable, but taking a small cushion/pillow can help with sleep, and countering the "numb bum" feeling.
there will almost certainly be an in built entertainment system so you can watch a few films on the journey. each company has different systems. again ask shearings.
have a look here for some tips on travelling by coach.
there are other threads on ferris/siesta which include a lot of information about how to make the best of your journey.

finally, when you get back please update us on how you got on with shearings, as i am sure there are many people on here who would appreciate any information you can provide.

Thank ytou for that, I will certainly let you know how it went

Cheers