I can totally understand your frustration.I finally pursuaded my wife to attempt IELTS a few more times. I’ve already maxed out my score with CLB 9, and if she also scores the same, I might jump to 458, currently I am stuck at 456. Not a major jump though but given the tough times forecasted ahead, whatever is coming my way, I am bracing it graciously, for there is nothing more left to score from. Lately, I’ve really started to think whether I’ll be able to make it even in 2020. God knows
For me, i am tired of taking IELTS anymore - Speaking and Writing have been my weakest points and i don't expect i can improve them in a short period of time plus i get tired after everyday's job ...
Don't know what to say to comfort you but 458 should stand a good chance in next year.
Wish you the best of luck.