I can’t help but feel sad

I have this feeling of impending sadness and angler that I can’t shake. It’s only been today but I can feel it building. I have had similar feelings a few months ago that lasted around a week with a two week interval of feeling fine. It’s like this heavy weight that only gets heavier.

I haven’t really ever told anyone but think it could be some form of depression. I really don’t want to feel this way and am not sure what brought it on or how to feel better. Any suggestions of things I can do to get over this would be greatly appreciated.