It really sounds like the urine is trying to clean you out, but it needs some help IMO.
The fact that you used to go once a day and now it's messed up, means that you were chronically constipated before, and there must be significant build up in you bowels. I'm not sure if you are aware, but anything less than twice a day (minimum two good movements, not small ones) means constipation. Ideally you should poop as many times as you eat per day, either just before or after you eat (there are differing views on this).
If I were you I would have some enemas. Say once or twice a day for 2 weeks, and see how you go.
Regarding the weight issue, when your bowels are clean and strong enough to work well you may find that your weight starts to normalise, however in the interim don't be too upset if there are some weight fluctuations. Sometimes things get worse before they get better.
If you want to do a serious bowel cleanse, my recommendation would be to read the book "Tissue Cleansing Through Bowel Management" by Dr Bernard Jensen
. It is the best book written on this subject IMO, and the reference material for many other books and programs on Bowel cleansing.
If you are keen to experiment with Castor oil, taking it internally will provide some degree of cleansing, but not as thorough as Dr Jensen's program.
You will find your entire health improves when your digestion and bowels are operating well.