Aw, I'm sorry your class didn't go well. I hate it when my machine doesn't want to learn what I want to!
Have you wanted a bigger machine before? If not, then I maybe don't start looking just because of on fabric bowl. Will your life be incomplete if you can't make those bowls? If not, stick with what you have. If you've wanted a bigger machine before, though, then maybe think about it.
You mention packing up to sew on a table height that isn't comfortable. Have you considered getting a little folding table to take to classes/retreats? I know a couple people that use them, and find it worthwhile. Here's one; there are plenty more out there, from a variety of suppliers.
https://www.amazon.com/Arrow-Sewing-...+machine+table
I sewed on a table like this for 2 years while at university; it lowered the machine, and folded up nice an small for my teensy apartment. It would be easy to take to sewing classes.
https://www.amazon.com/Lifetime-2824...justable+table
I think you've got the right idea, spending some quality time with your machine. I wish I was doing that today; my machine looks at me with sad eyes every time I sit at my sewing table and mark papers instead of sewing. Get something done, and hopefully it will all seem better.
<3