Health and lifestyle

Need some help! I've been wanting to lose weight for a while so been eating better and feeling better. For some strange reason I cannot get myself to eat anymore, I haven't eaten anything since Saturday and been drinking a lot so I've lost 7 pounds since then. I'm feeling really sick and in pain, the weight loss is great but this is not how I wanted to lose. Please can anyone give me some advice on what I can do to get my appetite back. Also I'm vegan and bike a total of 6 miles most days because of work.