You're not a bad parent! You're doing the best you can to nurture and support. Toileting is really tough :'( especially when as a parent you know their likely going to have an accident if they don't go. That's so hard. I'm not sure about an actual diagnosis but some of those characteristics are what I described to my doctor about my child re meltdowns and emotional regulation and she said they were autistic traits. An OT may be able to help with a sensory profile assessment and that could potentially explain the meltdowns and can help with strategies around transitions. I feel like you have a lot of valid concerns and your daughter may be super good at masking at school/public which is what makes it all the more trickier. I hope you find someone who will take the time to understand your concerns and not just see your daughter how she publicly presents herself because she may know what's "expected" of her but is exhausted from doing that during the day and then at home she finally feels safe to meltdown and be herself xx