Im currently doing an assignment for college involving the paired samples t-test using SPSS. I am having some trouble understanding why or what I am doing wrong.

I have run the pair sample t test on for pre cortisol levels and post cortisol levels, however, I have gotten a t value of -26.394 and a two-tailed significance value of 0.000. Of course when I look at the t table, my degrees of freedom is 99, however, the values do not reach such a high number that i have gotten for my t-value from the test. Have I done something wrong or am I using the wrong test or should I be possible using a non-parametric test?

Asking for a friend as I am in dire need of help!!