Predictive Validity

We have created a eustress/distress instrument for one of our assignments this semester, and I am a bit confused about predictive validity.

We have used the DASS and the PANAS for construct validity. And we are to use the Hassles ad Uplifts scale for Criterion Validity. We took a battery questionnaire of all three instruments twice (7 days apart) including our newly developed distress/eustress scale. So, I have reported the correlations for validities (convergent, divergent, concurrent). My problem is there are regression analyses to interpret, and I am not sure what I am to be interpreting. My understanding of predictive validity would be: to use our new scale to predict a criterion in the future, or to predict past behavior, which we cannot do with the data available.

I can see that the HUS accounts for 8.9% of the unique variance in the eustress component after controlling for demographics and the DASS. Does that mean that the HUS can predict eustress? Is this also considered predictive validity? This sort of seems like concurrent validity again to me. Sorry, I do not know who else to ask, and I have been reading up on it for a week now and keep confusing myself.

Thank you for your consideration.