This case seems rather complicated - only because you have diabetes - did you get diabetes recently or always had it? The reason that is important is because if you had grown to get it you can usually grow and adjust your body out of it through diet. At your age, for you to be getting all these complications means that you may have not eaten so well throughout your life or you could have some underlying problem that isnt showing because you are so young.
My boyfriend has a special condition called Caroli's disease( I am not insinuating you have it but giving yuo an example) . He always burps in these funny ways you mentioned etc. but he didnt know he had it until 2 years ago, at 33 years old- the doctors kept saying different things to him - like oh irritable bowel syndrome then they got rid of his gall bladder - my point is that doctors dont take this stuff seriously when you are young - they just say no worries eat better - if you can I would just go and get tests done - you are young and believe me what they say is true - the older you get everything gets harder. so take it seriously dont expect a quick cure-good luck