Jrjw,
As you have no parents, siblings or other relations who are JWs, there really is little reason to put on a pretence of continuing as a JW.
If you stopped attending immediately, even if you DA or were DF'd, you would suffer few negative consequences other than from the congregation members themselves. Since I recall you plan to relocate some distance away in the new year, any negative treatment received from the congregation, will be short lived.
As you have one child with the man you call your 'ex', whether or not you are awarded custody of the child by a judge, is not conditional on your practicing as a JW.
It appears that your ex is harassing you. Suggest changing your mobile number to stop his texts and calls. The only power he has over you, is the power you allow him to have and continue to accept.