You need to do a 180 and stop trying to hang on to the phone conversation! Do a 180 (I know this is hard!) and say you have to go and you end the conversation. You sound too CLINGY to me. And if you sound clingy to me, you probably sound clingy to him. They HATE this!
I hope you are going to rehab for YOU, and not your H! You need to do this for yourself!
When you fell THAT urge to call your H; ask yourself; "will this get me closer or farther from my goal". If you are truthful to yourself, we both know the answer to this question! Calling your H will NOT get you closer, but will only push him farther away. Unless it is an emergency with your son, I see no need for you to call. The time is not right for the calls, your H needs space, and you need to respect that.
Work on you, first, when you get better, keep working on you. You can not get your H back with the person you have become. WORK ON YOU!
Good luck! I will be checking to see how you are doing. Will not get the 2 x 4 out yet, LOL