I look at 'couples humour', 'couples life' videos on FB, etc. and just don't understand any of it

It's totally foreign. Makes me squirm/cringe mostly. Sort of like all sex and romance scenes in films and on tv make me want to turn away and not watch or (if in a film) get up and leave. Just makes me feel really uncomfortable as positive relationship experiences haven't happened for around 10 yrs.