I have not experienced what you are going through but all I know is that people need to eat healthy meals at least 3 times a day especially breakfast. We need food to energize us and strengthen our immune system. I think that you need to see a doctor in order to know what causes the lack of appetite and sluggishness that you're having.
I am a 20 year old female, and I am going through almost exactly the same thing. I'm super health conscious, and ve food, but I am too stressed to eat or I forget. Though, none of this is intentional, I feel unhealthily skinny. I have lost about 30 lbs. in the past 9 months, bringing me to about 103 lbs. I want to gain weight so badly, but it's like I just keep losing more. My therapist tells me it is an immune system imbalance? Lots of times it isn't just not eating causing issues. Are you getting restful sleep and exercise?? Stress and anxiety are crazy crazy things that can so easily cause all kinds of hormonal, emotional, and physical imbalances. Maybe pinpoint some stressful things that are easily in your control and work your way into healing those areas of your life. Perhaps that will trigger some positivity and growth in your life in general, this giving you more of an appetite? Remember, though, the stomach is a muscle and you probably won't be able to eat a lot initially, but little by little stretch it and make it possible to eat more and more each day. I hope this has been helpful, and I hope you feel better by now. I just didn't want you to think you were in this alone. I am living this struggle as well, and I know it is not as easy as a piece of cake. As much as I wish it was. It's really difficult and seemingly impossible to find others who understand this uncomfortable position. Thank you for reaching out.