What is appropriate for one person, may not be the same for someone else.
One thing for certain, once you DA, there is no way to unring that bell if you later find it was a mistake.
You may wish to initially fade or stop attending altogether to see how that goes. If tolerable, continue in that manner. If you later find it necessary or want to DA, you can then do so after appropriate calm consideration and without emotion or feeling forced or rushed.
Many JWs receiving a letter will not necessarily read it word for word but will simply scan through for specific words to determine the letter's purpose. Once they realize why you had written, many will not read it but will often discard or pass-it-along to an elder.
One JW belief is that we are each obligated and will be 'blood guilty' if we do not preach to and teach others. By attempting to 'Wake Up' active JWs, is that to appease that same learned obligation?
Sometimes, the less that is said, the better.