Celiac Disease causing nausea ?

(I am a 20 yr old female, and I'm definitely not pregnant) For more than 5 months now, I have been nauseous most every morning. I have to force myself to eat something, and usually the only thing I can tolerate and get down is something really sweet, like a dessert, which I know is not healthy but it's all I can handle. Lately, even just looking at food or thinking about what to eat in the morning makes me gag. By lunch time, the nausea is gone, but I have no appetite. I'll force myself to eat little meals so again, I'm eating something. Then by dinner time, things are normal and I'm very hungry. Not every time, but often when I eat out at restaurants I have diarrhea after. And my stools have been orange in color for about 5 months too. I also have suffered from fatigue for over 2 years. Lately I have been getting headaches a lot and occasionally will have numbness in my feet and toes, as well as pins and needles in my hands and fingers. Finally, I have had bad knee problems for almost a year now, and they are not healing near as fast as they should. My muscles are also really weak in my legs too. I'm wondering if I do have celiac disease, if it could be prolonging my recovery from the knee pain and also causing the rest of these symptoms. For anyone who has personal experience, I would really appreciate your input. Thank you.