Hairloss problem

I am 29 year old male who has suffers from diffuse hairloss for almost 10 years. i used to lose hair only at the top of my scalp. Because of this I always shaved my head. Somehow the hairloss instantly stopped shedding after shaving. I repeated this for several years and always it worked but then the hair started falling again after 2/3 months each time so I had to shave it off again. Since the beginning of february I started losing eyebrow hair and also hair from the sides and back of my head. I have never lost eyebrow hair of side/back hair. I also experience an itch in these areas. I lose a lot of tiny thick healthy hairs. Though my hair is 1,5 cm long at the moment. It seems my scalp is not able to hold the hairs that have regrown for very long. My hair is growing in different lengths. I went to several dermatologists and doctors. No one can tell me whats wrong. Blood tests came out all fine. Also I suffer from flaking , dandruff and extreme oily scalp. I started adding drops of tea tree oil to the baby shampoo that I use. This gave me intense relief. But then the next day my scalp becomes all oily again and itchy. Perhaps I suffer from some kind of FUNGAL infection?? I really hope that you can prescribe me something that can help me fight this problem as it had slowly ruined my life.I kindly thank you in advance for your reply!