Loss of appetite over...

So the past 2-3 months I’ve had a loss of appetite. I will eat but I get full very easily after eating small amounts. I know for a fact I’m not pregnant but my family thinks it could be depression. Honestly I haven’t been feeling depressed but the past few days I have been very anxious. It doesn’t explain why I’ve felt this way for months now though. I also get nausea in the morning. Usually it’s not as bad if I eat. Now let me release I am not pregnant I know that 100% so what else could I be nauseas and not hungry for. ???? And should I go see a doctor about it or leave it be. ?