Supposed to Have......

[Bobbert]

Today, as I was leaving a place, I attempted to say:

I better get going. I was supposed to have already left by now. I'm already running late.

What I said was:

Ya me voy a ir yendo. Se suponía que ya debía haber salido. Ya se me está haciendo tarde.

Please grade my sentences as to how close I conveyed those exact thoughts and how close I got to the phrase "I was supposed to have....."

I still struggle with the concept of "supposed to......"

[AngelicaDeAlquezar]

All is fine for me.

"Me voy a ir yendo" is very colloquial, but suitable for the context, I think.

[Bobbert]

Thank you for responding, AngelicadeAlquezar.