Here's a roundup of some of the most useful websites I've found that you might find helpful too.
Someone to talk to round the clock - you don't have to be suicidal to call: Samaritans
Information and resources on mental health issues: Mind
Mindfulness: Happify
Sex and relationship advice, ideas, and education: Meg-John and Justin
Emily Nagoski is a brilliant sex educator whose "mission in life is to teach women to live with confidence and joy inside their bodies": Emily Nagoski
Understanding porn and sex addiction: Mind map
Your personal trainer for reliable erections: Mojomen
An audio guide to mindful sex for women: Ferly
Information on sexual health and wellbeing for men, women and couples: Sexual Advice Association
Outreach and support for people affected by domestic abuse in East Surrey: ESDAS
Understanding gender: Gender Spectrum
Supporting gender diverse and transgender children: Mermaids
Information and support for LGBT communities and their allies: Stonewall
LGBT+ resources and support for younger people: The Proud Trust
Promoting GSRD therapy and training: Pink Therapy
Information and resources on polyamory and ethical non-monogamy: More Than Two
Eddie Ross, a young man expresses positive vibes and good energy for those experiencing mental health challenges: Into The Mind