I am not sure what I can really suggest as it sounds like you have some complex and perhaps chronic conditions with no simple fix, but I read your post a couple times and I do really feel for what you have been going through. I suggest that you do whatever you feel you need to do to get help with your symptoms, hopefully there is much more they can do to make you feel better than they are currently doing for you. I am sorry you have had such a rough time with your health at your age, life is really not fair sometimes. Good for you for keeping your weight up! I know how hard it can be. I also feel for you - doctors seem to want us to be visually wasting away before they want to help us - they don't realize that we are already trying 110% to make ourselves healthy again, and we are there to see them because it is just not working and we have exhausted our efforts. I think that you are very in-tune with your emotions and your overall situation and I hope that your doctors can see that and do not blame your GI issues or any other issues purely on anxiety. Of course it is anxiety provoking when we are losing weight and cannot eat as much as we wish we could. I am glad that you perhaps got some relief from the psychiatric drugs, what you are going through is tough.
It is situations like yours where we realize that doctors do not know everything, medical science is really a medical art and healthcare professionals are prone to bias - especially when they cannot help someone that is young and relatively healthy that they know that they SHOULD be able to help. I wish you strength in being your own advocate - sadly you have to stand up for yourself if you want them to listen and to do anything. I am realizing this fact more and more. I understand what you are going through sucks, and that you are probably getting worn down by it all as it has been going on for a while.
My partner has been good in reminding me to decide what I "want" from each appointment. I have had multiple symptoms that generally make me feel very ill all over. It makes me want relief from everything all at once, and sometimes when I go to the doctor I feel so hopeless I can barely describe my problems that are bothering me the most as I feel like the problems have sucked away all my energy to even ask for help and then the doctors have a hard time deciding what to investigate and they feel hopeless to treat any of my symptoms. It seems to work a bit better if I give them bite-sized chunks, as then I also know that everything will hopefully eventually be investigated. I feel like the only person I feel empowered to talk about all of my physical symptoms with is my psychiatrist - but sadly she cannot do anything about my physical symptoms.
Try to pick apart each problem and make separate appointments and try to get a plan to deal with each of them soon so that everything will hopefully seem less hopeless, decide what you "want" from each appointment, and perhaps write this down. Maybe you want your GI doc to give you a copy of your endoscopies, decide whether you need another one at this time or decide on a plan for treating your current symptoms.
Maybe try to write down your main symptoms and write down the plan for investigations and treatment as they come up, so that you can look at this sheet and remind yourself that someone does maybe care and that you have a plan and are not alone dealing with all of these problems. Do not let each specialist wait upon other specialists to treat other specialists' problems first - they can all be investigated and hopefully treated at the same time safely. I think the key is that you are obviously struggling and it sounds like you feel that you cannot live with your current health status, and it sounds like you want to get to a place where you feel a bit more stable and able to cope with everyday problems. It sounds like these medical problems have been a bit traumatic for you, and that is understandable - for your age you have been dealing with a lot!
Sorry for the long reply - I hope I have come across okay
I really feel for you and your frustrations with what you are going through. Don't be embarrassed to be a little pushy with the doctors - you are worth it.