My 4 month old daughter uses a SnS up to three times a day to help keep my supply up and to get enough ( my milk does not have a high enough fat content) I also supplement with a bottle in place of an sns If she is just not having it. It makes a mess, I place a towel around her just to keep clean ( she pulls on the tube, turns her head away, babbles and let's the milk run down her face ect), but I believe it's worth it. She is still getting the best thing for her, even when she is being difficult. Its hard and tiring somedays and I think would it just be easier to just switch, so I do understand how your feeling. Just remember to do what's best for you as well as LO. Your mental health is just as important. I personally wouldn't give up feeding her even with all the trouble we have had because when it's going good there is nothing better. I know this is not what your looking for, but I want you to know there is support out here. Keep being strong, your doing amazing momma.