First of all, I just want to preface this by stating...this is just my opinion, not the gospel. I don't want to offend anyone
I am a firm believer that not everyone can "stretch" a relaxer. I understand the concept, but I have seen too many instances where stretching has been counter-productive, as in your case. I don't think that one should relax any sooner than 8 weeks, but I certainly don't think that one should wait beyond those 8 weeks, if it's going to lead to problems.
With regards to your ends...again, some people don't require frequent trims. I for one, have not have a real trim in a year, HOWEVER, I get dustings (when the stylist chips off about 1/4 of an inch OR LESS) every 8 - 10 weeks. I do this religiously and maintain more length than I would if I got infrequent trims, or even if I got frequent "regular" trims.
Lovely, I think that you may need to re-evaluate your current regimen and adjust it to suit YOUR needs.