Help with understanding docs and making them understand me? (The relationship between doc and patient)

24 M, healthy, In many instances when I go to doctors for things I feel like I'm being brushed aside and I don't know how to prevent that. Just as example, I have a case of dandruff and itchy scalp since 12-13 y/o, at that time I was prescribed a medical shampoo with an active ingredient, and while it did help (only when using it) with the dandruff, it didn't help with the itchy scalp, so I went back again a year or so afterwards, with complaints about the itchy scalp and reported how the shampoo helped with the dandruff but only in active use and after I finished it and was left without for a week or so the situation reverted back to how it was, and was just given the same shampoo again. And when I say itchy scalp it sometimes get bloody, from blood that clotted on my scalp from my scratching. This has been this way for multiple years with different dermatologists that I visited. Is the problem with me? Or are the doctors not doing what they should/they don't have other options (or other easy options?).