The saying is "get back on the horse that you fell from"
"get back on the horse that buck and threw you off, or shied sideways and unseated you, or reared and you went off of backwards or bolted and smacked you off running under a tree limb."
KNOW THE DIFFERENCE.
Maybe not in some cases though.
Okay back on topic.
Bottom line, horses are going to frustrate you sometime, but eventually I believe you'll find 'the one'... It may or may not be the one you currently have, but there's a horse out there that you can have a great time riding. Just don't get discouraged!
I agree with previous posters, maybe your trainer isn't the best. "Kick 'em harder" is never the right answer IMO.