Need advice

As for the oilyness problem, if it looks so oily after what you feel is too short a time, maybe your shampoo is too harsh.  Try diluting your shampoo 50/50 with water (roll it slowly to mix it, don't shake, and only make up the amount of it you will use each time to avoid it sitting around diluted).  Washing with that will still lather, and get your scalp clean, but it will strip less of your natural oil from your scalp and your scalp will stop overcompensating by producing so much oil. 

As for the thinning, our hair does change with age.  If you really feel its getting too thin, visit a doctor and get blood work done to make sure everything is okay.  About the Viviscal, since your hair looks thick after you wash it, you probably don't need it.  I think the weight of the oilyness is just weighing your hair down and making it look limp and thinner from what you say.

A multivitamin a day may help if you don't already take one, just to make sure you are not missing something with your diet  (but don't overdo vitamins, taking too much of some things causes hair loss and worse).