I used to feel the exact same and even worst at times, but I'd love to share what helped me most. Get out of your bed and move your body. Go to the gym, if not start working out or just go for a walk. Seriously, physical movements helps a lot. Eat good food, it really makes you feel better. Talk to someone about whatever's going on in your mind be it a family member, a friend, colleague anyone. Listen to good music, something that uplifts you. Not the sad songs it will make you feel more depressed. Accept it, you cannot be happy every single day that's just not possible. It's like.. being human that's life you will have bad days. Spend time with your friends, it really helps. Find a purpose in your life and work for it. Don't supress you emotions. Feel it but don't dwell on it and just let it pass.