Stiffness around hip/lower right abdomen

Hi, i have been experiencing a strange sensation at my right hip. It is a sensation of stiffness and usually the lower right abdomen feels very tight especilly when i twist in any direction. Sometimes if i sit for too long in my car (i drive a manual) my lower right back begins to hurt to the point where the only relief is to walk or stand for an extended period of time. Also walking/standing relieves my tightness on the side. However sometimes i feel like something is down there like a knot or bubble, especially when I bend down (tie shoes or do sit ups). I have been tested for a hernia and I don't have one, my blood test (general) is fine and my insurance refused a ct scan. This has been ongoing for 3 months now.

i was wondering if it is related to the psois muscle? abdominal muscles? hip bone tumor? or any other growth/tumor? anything a long those lines, i am at a loss at what it can possibly be.

so please if you have any ideas, suggestions or words of wisdom..please help...im getting very nervous, frustrated and depressed over this, especially since doctors are just simply telling me to forget about it without doing any tests or scans or telling me what to do about it.

thanks,
Stan.