Reducing contact because my heart just isn't in it.

I’m so sorry that you’ve found yourself in this situation, lovethepuppies. It’s a credit to you that you are thinking of them & not wanting to hurt them, even though you are hurting yourself.
You say that you have finally reached this point….have you tried to explain to them how you feel and what has brought you to this point? Do you think it is possible for you to work with them to improve things before taking such a drastic step, which would be so difficult for all of you?

Yes, I am aware. I have adult children. I did raise them very differently and, fortunately, it seems to have worked with them.

Of course, just reduce the amount and duration of texts, phone calls and emails. Allow them to contact you first sometimes.
Maintain a relationship and see what happens.Parents aren’t perfect and have their own troubles and insecurities.