The internet can be a very useful place to gain information about your condition and treatments. However it is potentially a dangerous place to go if you are looking for a new diagnosis.
Remember - if you are asked for any personal information before you can proceed to a certain area, or are offered a treatment for sale at the end of the process - you have probably just read an advertisement, no matter how official and academic the website looks.
None of the reputable charities or universities will ask you to 'sign in' in order to gain information.
Here are a selection of sites from the UK I am happy to steer people towards. There are of course numerous others.
All of these links were working at the time I published this page - If you find any that have broken please e-mail me to let me know -many thanks.