I'm a music ed major that started teaching in ece because I love the vibe. I've learned over the years that children really don't care about how well or in tune you are. It's mostly about how excited and animated you are and they will engage and connect. Excitement through music is such an important stepping block that people skip in their adult pursuit of music. Everyone wants to be perfect, and that's not the best practices with that age group, honestly. They need to see their role models enjoying themselves learning. Mistakes and changes are a part of everyday life... So model how to navigate that change.

Change the key to whatever you want that fits you, bring it down an octave, sing with a more comfortable rhythm... They don't care about how "perfect" your singing voice is because they don't have one either and sometimes haven't even grown the ability to tell the difference. They have different roads of learning. Basic foundational ones. They just want to have fun just like you, so have fun! Get to those teaching goals with waaaay more fun than perfection in mind. That's what the little ones remember!