Dealing with IBS-D: Frustration and Hopelessness

I'm getting really frustrated with eating and just food in general. Currently I follow a strict fodmap diet, but at this point it seems that regardless of what I eat, my body just cleans out my entire system as fast as possible. I feel so nauseated, fatigued, and drained. Then, as a result, I don't feel like eating. But when that happens I almost pass out due to (my doctor thinks) hypoglycemia type episodes. So although I know I need to eat something, I don't want to. I'm so done with this cycle. I feel very hopeless dealing with ibs-d; I haven't found any sort of management that works for me right now, but I'm trying to hold onto the fact that I have a new gi specialist appointment next week. If anyone has any particular strategies for dealing with this (mentally or physically), I will certainly take it!