There's no such thing as over sensitive, and your feelings are always valid.
There are no rules about how sensitive we should be, so if you feel oversensitive in a relationship, you are too sensitive for that person's preference. And since you're the one who gets to decide who you are, nobody can tell you you're wrong.
Respect your feelings. Always. A decent partner will, too. It doesn't matter how silly the feeling seems, logically. Take a fear of spiders (in the UK) It's completely bonkers. We have no dangerous spiders here, and even the enormous ones are only half the length of your finger. But a respectful partner will respect your fear of them; take them quietly outside without bothering you. A crap partner will tell you you're being stupid and you can deal with them yourself, because they can't be bothered and spiders can't hurt you anyway, idiot.
Find a partner who accepts you and the way you think and feel. Someone who wants you to do things that make you happy, even if they seem a bit odd or don't particularly make sense. But most of all, you need to accept the way you think and feel. No more 'Am I being too sensitive? Is it me or is it him? Are my feelings valid?'
You feel what you feel because you are who you are. No questions, no challenges.