Am I doing this right?

Does this ever get better? I am in to this since January/ February and we are now in the middle of March and it seems like my hair has multiple personalities. One day after washing, it is light and moves and is happy and shiny and the next time after washing, it is heavy and limp and ‘thick’. I have used bicarbonate and ACV. I used honey and ACV. I tried solid vegetable/plant based shampoo and ACV. My hair seems healthy. I am not shedding as bad but every time I have to go out, I look like a slob and the days I stay home seem to be the only magical days that it looks light and easy breezy. I have bottom of shoulder blade length medium thick dark brown hair. I have waves some days but not curly. In general I would call my hair straight. I only washed it once a week, sometime twice, previous to this adventure. My scalp and hair seem to get tired of shampoos and conditioners quickly, so I always have half finished bottles kicking around, and my scalp is itchy and my hair gets finicky. Does anyone have some encouragement or suggestions? Is this normal? Am I not doing this correctly? I am only washing it once a week-10 days trying to really give this my best attempt. I must say I love the ACV rinse. It feels amazing and my scalp hasn’t been itchy.