EF ... your ideas sound nice but do they help in this situation? Crumpet does not feel valued by her b/f. The fact that Crumpet feels threatened shows me that b/f doesn't make her feel loved. If he does love her, he would want to reasure her of his love and not tell her to shut up.
If she gets on with her life and learns to value herself it won't matter to her if he loves her or not. She has to love herself ... when she is confident in her own value, she will have to decide if b/f is even good enough for her.
Right now she allows him to belittle her ... she is desperate to be loved and accepts this treatment. When she learns to love herself, not he or anyone will be allowed to hurt her. It all boils down to self-esteem. What bothers me is what pleasure can he get from keeping her down.
Crumpet thinks she has jealousy issues. Maybe she does. I think she has bad b/f issues and self-esteem issues.