Try to expect that she will likely not get back to you immediately. Assume she will take a couple of days to answer you, and don't pursue her for an answer.
Expect that she will take the boundary seriously, which means, you really do need to consult a lawyer within the next week or so. If you don't, then the letter will render itself as simply more cake eating opportunity for her.
She may be angry at your "demands". You said she is a control freak, so expect her to freak out. Expect her to possibly come back with a heated answer, but don't expect that to be the last word. If you and she do end up divorced, that is a long process and you will definitely have more time for more words later....so just know that even though you have to follow through and talk to an attorney, it doesn't mean there won't be time for her to get her act together before it is a done deal.
Just don't expect her to get her act together, because she may not. That is up to her to figure out for herself.
Expect that you will need counseling through this difficult journey, and get some.
If you tell her in your letter how much you miss her, etc. don't expect it to make a difference. The part in the letter that will make a difference is the part that implicitly says "you WILL respect my boundaries, because I'm taking my cake away". This will make her also respect YOU, and you CAN expect that!....if you really hold to all the letter says.
You can also expect a lot of support around here, because so many others are going through the same or similar. Do you read and post on others threads? That helps sometimes to do that, because we all need that support from others who "get" what we are going through.
