You can love your mother but you don't have to like her. She is controlling you. She is only concerned with her interests, not yours. That is NOT a mother's love. I don't see Todd sticking around for the long haul. What man in his right mind would stay in this dysfunctional relationship you have with your mother? And if you think after you are married that things will change...no dear, they will only get worse. My advise would be to make a decision...Todd or your mom. If you pick Todd, you may have a real chance at happiness. If you pick your mom, you will always be alone. You can be respectful and put your foot down at the same time. Set your mom straight now. Tell her that she needs to stop all the trouble or you will have to cut her loose. It won't be your fault. You just put the ball in her court. She will either have no choice but to stop meddling in your relationship and stop causing trouble or she will no longer be part of your life. I know it seems harsh but if you don't put your foot down now, you never will and that is what your mom is counting on. The fact that she is using your daughter in all of this is disgusting. Again, that is NOT a mother or a grandmother's love. If this were happening to someone else I KNOW you would tell them to get their mom in check.
What your mom should have done was say she didn't think Todd was the man for you but that she would always be there for you and support you always. I hope you can find some happiness.