Bunning and stretching relaxers too long (6 months) caused my fine, delicate strands actually contributed to my 2" cut setback. I will never do that again. Sounds like your reggie is fine, but I would suggest the following:
1. Cut down on the heat, perhaps cut back to once a month or once every six weeks. That blowdryer ain't no joke.
2. Clarify your hair once a month, since you're using so many products. You may get some buildup in there.
3. I find that protein, even in the smallest amounts, can do damage to my hair. Finding that protein/moisture balance has been the hardest thing. I just now got my hair to stop breaking. I found the culprit products that I was using that may have contributed to the breakage, studying the ingredients and found that each one had a trace amount of protein. So I ditched those and found ones that had more moisturizing properties. It may be different depending on what your hair needs.
4. I cringed at the stocking cap. Stocking caps pull my hair too much, especially the sides. I know that some women here use them, but I find that they cause some kind of static friction that may lead to the pulling of the hair.
I stopped bunning and now just where a curly updo with as much of my ends tucked in as possible.
I lost 2", 1" back in December when I got my hair done. I ended up cutting another inch in January. However, my hair is growing because I'm basically back at about 1" or so from APL. So now that I know what worked and what didn't, my hair is finally thriving. I, too, have slow-growing hair but finding the right kinds of products is helping. I think adding Ayurvedic remedies is helping as well. Alma, shikakai, coconut, Bhringraj oil, henna and others do help strenthen the hair but I can't use the powders too often on my fine hair.