As usual, Bain has given a comprehensive answer and some good tips. When your Gastrointestinal doc keeps telling you to give it time, he/she is absolutely right as these things do not heal overnight and it sounds as if you had some major surgery.
I would just like to point out that one of the major causes of all sorts of gastrointestinal problems (including cramps)in 'normal' people is anxiety. Thus, what you describe in terms of anxiety and sleep deprivation, will not be helping. It won't hurt to reiterate what I have said many times about anxiety. It is a term that describes a specific form of 'fear'(usually a generalised mild version). 'Fear' is an emotion and emotions are notoriously difficult to control and manage. (largely because they are 'instinctive' and not dependent on the thinking process to start them off). Fear is an instinct associated with survival and, as such, is very useful in certain circumstances where an instinctive response is required. Unfortunately, with chronic complaints, this instinct is often inappropriate over a long period and can cause all sorts of peripheral problems such as those you describe.
Unfortunately, there are very few psychiatrists who fully understand the nature of emotions and they therefore tend to 'treat' the problems as if they are 'medical' rather than emotional, psychological or social, which in esssence, means they will prescribe medication for something that is not (always) a medical problem.
Many psychotropic drugs are not originally designed for what they are now being prescribed for and, if you read the so-called side-effects, you may well find that they might be actually causing or exacerbating the problems you describe.
Managing and controlling emotions is usually the realm of the 'psychologist' but unfortunately, there are many of them, who also do not fully understand the underpinnings of emotional energy so, in recommending the psychollogical approach, I would caution against using just 'anyone' with a psychology title or degree. If you can find someone who specialises in emotional control, then you might have some chance of managing this aspect of what is probably a complex set of problems.
On the other hand, emotional problems are internal and personal so, if people put their minds to it, they can often organise-themselves to recognise the problems and plan to do things to 'MANAGE' them more effectively.
NOTE: it is impossible to 'cure' instincts but it is possible to control, manage, channel and use the energy for postive purposes, rather than letting that energy control you.
I hope this is helpful