Descriptive graph line

Hello!

I am new to PowerBI and I'm struggling a little to get a certain graph line. 

I want the output to be like this: 

But I am only getting this instead:

So, I need the lines in the graph to represent the study groups and the two moments of anxiety measures (before and after) in the X-axis, but what I am getting is the opposite: groups in the X-axis and the lines representing the mean values of anxiety...

Also, the table with the data I need to put in this graphic looks like this:

Can somebody help me with this, please?

I thank you in advance!