Kinda clueless about the statistics of my thesis

First of hello everyone and sorry for my bad grammar or "technical" english. I rarely write about statistics in english^^.

So I am working on my Bachelorthesis atm and have it nearly finished and wanted to do the t-test. The questionnaire was t 10 questions/statements/items aked twice. The subjects were confronted with a situation and then had two answer the 10 items for the first time. After that they got confronted with the same situation but with a change in it and got asked the same 10 items again. So it should be a paired t-test right?

The answers to the items were coded from 1 "I disagree completely" to 5 "I agree fully". The items were all phrased positive so a high answer score is seen as "improvement".

Now what confuses me are the values I got from comparing the item-pairs.

For example Item 1 before (153 subjects did the questionnaire)

Mean: 3,17647058823529 (3,18); S1: 1,02974 (1,03); N: 153

Item 1 after:

Mean: 3,73856209150327 (3,74); S2: 0,89859 (0,90); N: 153

Difference:

Mean: -0,56209; SD: 1,14806; N: 153

Results:

df=152; t-statistic=-6,03621232296233; P(T<=t) two-tailed=1,15807671639069E-08; critical t-value two-tailed=1,97569393

So yeah I am really clueless atm what this means as two people (both Psychologists so at least somewhat versed in statistics) got really confused looking at the numbers.

Did I do something wrong and if yes what and how can I interprete these values?

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