I know how you feel Ellen, and sorry you have gotten the high FSH diagnosis. I also conceived very easily and naturally at 37. Started trying for second at 38.5, got high FSH diagnosis (also 15) at age 39. I am sorry to tell you that I have been trying for 2 years and no luck yet (just one m/c). But I have certainly seen many women on this board get pg against the odds so there is certainly hope. You may want to read the over 40 and high fSH board as well as it is very active and lots of pregnancies lately.
Don't worry about not being able to do IVF. I tried it and failed terribly (not enough eggs). There have probably been more naturaly pgs on this board than IVFs (though I can't say for sure). I am currently doing natural IUIs. There are no drugs, my doc just monitors my cycle and we do the insemination when I am ovulating. It is low cost. The main reason we are doing this is because my DH has low sperm count but i think it also helps to just have the monitoring so that you know that are growing a follicle and that you are having sex at ovulation time.