StillIntending, there are a lot of non-pharmacological interventions you can try to address your mood disturbance. If you're a vegetarian or vegan, low vitamin D can lead to depression, and low b12 can lead to all kinds of mood and psychotic disturbances. Many vegans get their D from UV treated mushrooms (D2) or through sun exposure (D3). B12 fortified foods are vegan. On the other hand, low folate intake may also lead to depression. Many foods are fortified with "folic acid", which is fine, but naturally occurring folate found in dark leafy greens and other veggies is preferable because there are no negative effects from getting too much. A big one is inflammation. A lot of our favorite foods raise our levels of inflammation and lead to depression that way. Exercise is important too just for all-around health, and it may lower inflammation by lowering blood pressure.

I can't recommend, and advise against, taking any drug or supplement since they can easily have adverse consequences. For example, if you don't actually need it, an anti-inflammatory may make things worse. If you are taking anything unusual, try going without it for 2 or 3 weeks.
Only take a pill if a professional recommends it, except widely recognized vitamins, which are probably fine.