I can't cowash long-term either. What I do now is cowash a MAX of twice before shampooing again. I also had a problem with my hair feeling like straw otherwise. Plus my scalp cannot handle no-poo. I've also given up on trying to go sulfate and cone free. My hair LIKES those things, so I'm not gonna bother trying to avoid them anymore.
You and me both! My hair NEEDS regular trims. I started trimming yesterday and will finish today, and I can't wait. The only thing that being natural and low-heat does in terms of trims, is that I trim more single-strand knots than split ends. That's it. The fact that I need regular trims is non-negotiable. Right now, I'm trimming every 4 months, and that seems to be about right for my hair. I cut off between 0.5'' and 1'', depending on the section I'm cutting. I don't care if it's a bit uneven since it's not noticeable.
Another thing I want to add to your post, based on something I'm learning about my own natural hair, is that I also need protein. I thought protein was just for people with relaxed or colored hair, and for high porosity folks. I have very low porosity, and virgin hair, so I never protein DCed. I did it last week for the first time since going natural, and WOW! My hair is behaving completely differently! No more. I'm definitely going to incorporate it regularly.