Wow, that sounds really awful. I am sorry you are dealing with this. I have a few questions about the celiac disease:
Have you visited with your physician about the fact that you don't really feel better after having begun the GF diet? There is a small number of people who don't improve onteh GF diet. This is called "refractory sprue". If you are concerned you can have him schedule another endoscopy to check the status of your villi. If they are still flattened after three years, then you definitely need medical attention for that.
I would also definitely mention the part about the bleeding. I am not sure what that is related to and it could be a number of things. You state that fruit tends to cause stomach upset...is this citrus? Ulcers can cause bleeding and lots of pain, particulalry with citrus. THey can be caused by an H.Pylori infection or by the overuse of NSAIDS (Ibuprophen, Naprosyn, Celebrex, etc).
Untreated Celiac disease can eventually lead to Colon Cancer, statistically speaking, there is an increased rate of lymphoma for untreated celiacs than the rest of the population. I would not have that as my first suspicion, however.
There are a lot of possible scenarios for your symptoms-if it were me, I would go back to the GI doc, tell him about all that has been going on and request an endoscopy and colonoscopy. This can help get to the bottom of your myriad symptoms and put your mind at ease.
Hope you get to feeling better soon.