I mean, be conscious of your needs, but anyone saying "you're too sensitive" is pretty much universally an unhealthy person to be around unless there's some real nuance to the situation. It means they're dismissing your emotional reactions as unreasonable or otherwise not worth respecting and that's basically abuse 101.

Find people who get you and accept you as you are. If there's something about yourself that you struggle with, work on coping techniques and the like, but ultimately anyone who doesn't respect you is going to abuse or hurt you even if it's unintentional on their part. It's why we're several times more likely to be abused than neurotypical people: we're constantly told that we're being unreasonable and we tend to be far more accepting of others than they are of us, often ignoring abuse because we're taught to internalize self-hatred from a young age. At least that's my perspective as an autistic person with C-PTSD and a heck of a lot of trauma related to this sort of thing exactly.

The correct response to someone seeming sensitive or expressing a boundary is acceptance and respect, possibly followed by discussion on those terms when it's not urgently in need of addressing. Ignoring boundaries is almost always either abusive or neglectful. Slips are going to happen, of course, but "you're too sensitive" is an intentional attempt to dismiss your boundaries, not a slip barring exceptional circumstance.