i got", "I'd've"
what's wrong with the phrases. For my money, they are perfectly normal.
As I said it depends on what you mean by "writing skill". If those things look normal to you in writing, then I don't understand what exactly you want to improve. Probably spelling or typing speed.
For me speaking and writing are games with different rules. Not totally different, but still there is a difference, and if you want to be good at writing, you should know it. By "you" here I don't mean you personally (just in case you are about to lose your temper again). You personally seem to know best what you should do, so good luck on your way to perfection.