Firstly, sayings/proverbs like this can be a great trigger for stories in that, yes, you can use them as titles, but I find them more effective as themes. The great thing is many of them can be used for either comedy or drama (or both!).
Secondly, and this is borne out in other areas of life, particularly sport, practice does make perfect. You can't reasonably expect to make progress without putting the hard graft and time in and accepting the fact it will take time to improve and build on where you are currently as a writer. I am a tennis fan and was thrilled by all the British successes over the final weekend of Wimbledon but I am in no doubt each and every one from Andy Murray downwards would have spent years getting to where they are now. Just as there are no shortcuts here, there are no shortcuts in writing either.
I found rejections easier to accept on realising (a) everyone gets them, (b) there really is nothing personal about them, (c) receiving these is part of every writer's "apprenticeship". On accepting that, it is easier to come to terms with the fact that you've got to take the long view when it comes to publishing.