I retired from teaching in 2012. You are entitled to 6 months full pay/6 months half pay. It was worked out that my pension came into effect as soon as my sickness entitlement ended and not a day before! This also means you get as much as you can out of your pension as you’re obviously paying into it whilst getting sick pay. I was granted the higher tier which means I won;t work again (I have PPMS)
When it’s time to make your application (maybe 9 months or so from now if you’re not off sick at the moment) send copies of every letter. As Carolyn says they need so much evidence. I also got my neurologist AND GP to complete the application form as well as the OH doctor. Everyone has a slightly different slant on the questions. Then keep copies of these as they’re useful evidence for DLA/PIP/ESA!!