PJW, you really have to bite the bullet and ride through the hair cycling. What you describe is very common.
Let me try to explain a little bit to you about the nature of hair growth, and hopefully you'll feel a little more at ease about your situation. Basically, hair grows in cycles. It starts, takes about three months to reach a length to pop its head out and be seen above the surface of the skin, and then it continually grows for a few years. Then, the hair follicle stops growing, and the hair shaft comes loose from the follicle base, and it sits there, in your head, but not attached, for months. Then, inevitably, the hair comes loose and is shed. At this time, the follicle rests for a few months, and then begins production of a new shaft.
Now, with male pattern baldness sufferers, the follicle is under attack from DHT. As a result, the new hair that begins production is of smaller diameter than the previous one. So, when the new hair pokes its head out from the follicle, it is more thin than the previous one. This hair grows, sits, then gets shed, and the next hair is even more thin than the previous... proceeding until the point where the hair is so small, and has no pigment, that it is almost invisible to the naked eye and adds no cosmetic benefit to the overall hairline.
The point I am trying to make is that hairloss takes a lot of time to progress. The flip side of my point is that hairloss treatments, treatments that reverse the thinning and keep the hair in growth mode longer than would have been without the treatment, ALSO take a LONG time to take root and begin showing visible benefits. All the while you are waiting, your hair still continues to cycle. So, don't let the shed cycle discourage you, instead fasten your seat belt, be patient, and give the treatments time to affect an ever-increasing number of hairs as your hair cycling continues. Chances are, given the time frame you have been on the treatments, that the hairs you are shedding were NOT initiated into growth by the treatments (they were already IN growth mode when you started them)... so, by them shedding, it allows the follicle to begin producing a new hair shaft, one that has been "fertilized" with minoxidil from inception.
One other thing to keep in mind is that the hair cycle and sheds do not occur in an even and consistent way over the entire scalp. The scalp is a funny thing. Hair shedding never happens at a statistically EVEN rate throughout the year, it is usually characterized by long periods of below average shed rates, and then you will have an episode of above average shedding. With time, the shedding stops, and you go back into a low shed phase once again. So, don't let sheds bother you. They can be scary, but you have to ride them out.
Keep in mind that sheds don't hurt the hairline in the long term... what REALLY matters is how thick the hairs will be that grow in to replace them.[/code]