I tend to agree with the concensus ~ there are two separate issues at work here. When problems arise in a non-standard relationship, it's easy to blame the relationship structure when that may not be the problem. The relationship you describe with partner would be far less than satisfactory even if she were not poly. There are specific problems you cite which could be addressed if you are both willing.
Now you can ask yourself, if the problems you have with your partner could be resolved, would you still have an issue with the mono-poly structure of your relationship?