My bird is really sick I need some care advice!?

You strike me as a very caring person,you are giving your bird loving care,this is something money can't buy.Your description says it is a very sick bird indeed,probably injured too;keep the wound in the wing,clean & dry.Use an antboitc powder or ointment over it,any chemist or pet shop should stock this & it is not likely to bevery expensive.You seem to be looking after all it's other needs very well,keep it up.Inspite of all this if the weak little bird gives up,then you will have the satifaction of knowing that you have done all that you could.