I would suggest that if the pain is where you say it is then it is much more likely to be a gallstone trapped and causing biliary colic than a kidney stone.
If it is a Kidney stone - you can flush that out with drinking 3-4 times as much water as you would normally be drinking. It is horrid force feeding yourself water, so also have tea, juice, still lemonade - nothing fizzy though.
If it is a gall stone billiary colic then this has a pattern of behaviour. It will be worse after a heavy meal usually in the evening because most of us have supper as the biggest meal of the day. And thistype of pain can keep you up for hours at night and no amount of pain killers or digestive treatments like ant-acids will calm it down.
But it won't be every single meal that causes this - but can be as frequent as every couple of days or so. If you cannot find someway to have that checked out by a consultant gastero-enterologist then you will be best advise to avoid eating any meals in one big go. Nibble foods in small quantities throughout the day instead. So as not to trigger the gall bladder to fill up and cause pain. Avoid all fatty foods completely. The bile is produced when you eat fatty foods as it is needed to break down the fats as they pass through you. So if you don't eat any fats - it won't need to get to work and should stay pain free and calm.
It is possible there is endo on the diaphram or the tubes leading to the kidneys. But if it is endo - then the pains are going to by cyclical coinciding with your period and not causeing much discomfort in between times when it is actively bleeding.
You should probably try and have a Liver test to see if that reports any problems with your liver which is also on the right hand side in most people.
As biliary colic pain the world No.1 cause of pain in that area of the body and the owrld No.1 reason for any stomach surgery....my hunch is that is probably most likely the problem here too.
It hits men and women in the same age brackets as endo hits women, and is caused by the fatty western diets we are all brought up on. Over the years these creat calcified stones in the gall bladder and these rattle around with no problem at all, till one day the space for the gets just a bit to overcroweded and one or more stones gets pushed in the exit pipe of the gall bladder preventing the bile from flowing nicely in to the digestive system. The bladder fills and fills but not emptying out the pressure builds up and it HURTS.
If willease off in the hours afterwards as the gall bladder does eventually leak out enough bile to calm down a bit. This is very common for endo ladies - but also very common in the population in general.
If it is that causing your pains - then having the gall bladder - complete with all the stones- removed is usually a 100% permanent cure for any pains in that area. It is a keyhole lap op procedure - much like the endo ones. The fact that you have said pain meds doesn't help - is indicative of gall bladder pain too.
That's my hunch on this one- and is easily resolved - but will take a surgery to remedy the situation once and for all.
I'd suggest you ask relatives or the bank of mum and dad, or someone you know can afford to loan you the money to do so. The quicker you get this sorted out the quicker you can get back to normal and working to pay them back.
Try the eating no fats and munching through the day not having full meals as that will help in the interim. Good luck getting this resolved.