I'm sorry you are feeling this way - I've been there and it's horrible. Why are you feeling so low? How long have you been feeling this way? Is it situational? If you feel comfortable in sharing more details, you may get better feedback.
Without more information, I can say is that these feelings are usually temporary. There are some things you can try to lift your mood. Getting enough sleep, eating healthy, and exercise really help. I absolutely loath exercise, but it does make a difference. I try to walk for an hour a day. If at all possible, try to be around people, even if you don't feel like it. Are you close to your family or have any close friends? Try to distract yourself with something you enjoy. Make a plan to do something tomorrow - anything, and make yourself do it. For years I struggled with depression and feeling powerless. When it would get really terrible, I would would make a list of stuff I wanted to change, and then categorize them by level of difficulty and the amount of time it would take. More complex items that involved multiple steps I would create substeps (bullets). I would then make a point of trying to complete five things a day on that list. Some items were easy and would take an hour, some would take weeks or months to completely finish. I would cross an item off the list as I finished it. The complex items with substeps would be crossed off when all the substeps were complete. The experience was empowering, and really helped me to put in perspective how much control I have in my life. I also felt good about accomplishing stuff, and it would help pull me out of depression. I know it sounds trivial and ridiculous and may not be applicable for you, but it did help me. The point is to consider why you are feeling this way, and try to brainstorm ideas to fix it. It's within your power regardless of whether it's situational or mental, you can take action to improve your situation.
Again, the way you're feeling now is temporary. Circumstances will change and eventually it will get better. I hope to hear back from you, and hope you start feeling better soon.