Aside from stuff like the wrong products (too much protein, too many humectants?) physically weighing your hair down, there could be other causes for your hair loss and for it appearing straight, from anemia to stress to hormone changes to bad eating. You should definitely check with your doctor and get blood work done to see if any of your values are out of the normal range. This can provide clues. If it is too expensive to see another doctor, your gynecologist can order blood tests and ask for a urine sample at your yearly appointment. You can ask to have your hormone levels and thyroid tested in addition to the other basic stuff like cholesterol, blood cell analysis, etc.
I had an experience in 2005 where my hair "went straight" after a hair cut. Years later, in 2008, we discovered I had Celiac Disease (I cannot eat gluten otherwise my small intestine freaks out and I donīt absorb any nutrients, like iron). All my values on the blood test results were out of whack until I started the gluten free diet, and now they are all 100% normal. However, as a result of being anemic and generally not well nourished, my hair had thinned out a bit and lost its curl. Now it is thicker, though not like it was in high school! (Iīm 30.)
Look at this pic from June '09.
I'm in Bolivia and I don't think it was a particularly dry climate, but my hair is almost straight without having been blow dried. (And I'm also chubby haha). In 2009 I had way less natural curl but I also didn't know how to bring them out, nor did I have any decent curly hair products while living in Argentina. You are in a different situation because you're already a CG. Do you get your hair cut dry but a CG expert?
On a side note, our hair can change (like every 7 years or something someone once told me) due to normal hormone changes. It is also common for women's hair to thin out as we age. Our genetics play a role in that.
Bottom line: definitely see your doctor and try to eat a balanced diet including omega fatty acids, and drink water throughout the day. My family had a golden retriever whom we fed fish-oil pills. I'm not sure why they originally recommended them, but they made his coat amazing: it was noticeably shinier and very healthy!
Hope this helps.