Please help my son

Hi everyone I don' know where else to turn I don' speak to my family and have very few friends , my little boy Lewie has been in hospital since he was 7 months old he is now 14 months , he is failing to gain weight and grow as he should be and the hospital are none the wiser as to why this is happening , I basically love at the hospital with him but I have 2 other children and as I can' work as I'm at hospital 24/7 I have got into aload of debt on top of that my son needs specialist tests doing which I have to go private to have this done and I simply can't afford it , times are so hard and I'm hoping someone out there can help I can' begin to tell you how ashamed I am of writing this here but I literally have no one to help thankyou thankyou for reading x