What is the analyse type that I can run with both independent variable and dependent variable as repeated measure? Urgent thesis submit is very soon

Hello, everyone.

My study is about the product design effect on consumer preference.

In my survey, I presented the respondents with pictures of 2 products (new Vs prototypical) and ask them to rate their relative preference on a 7-point scale.
My measurement question for my dependent variable was:
For category 1, which product would you be more likely to choose?
1= definitely product A, 7= definitely product B

And then asked respondents to rate each product separately on the design newness, prototypicality with:
How do you consider the design of the product?
1=prototypical, 7=new

The design was 2 (product type: new/prototypical) x 3 (product category). Both were a within-subject design.

Q1: What is the proper method in SPSS to analyze the main effect of product design on preference?

Later, I added a mediator to my study, the mediator (Function quality) was measured on a 7 point scale (1= Very low, 7=very high).

Q2: How can I analyze to know the significance of the mediation effect.

Ps. My DV is always a repeated measure.

Thank you in advance for helping me. I'm running out of time and couldn't find the best statistical way for obtaining significant results.