Don't drop any responsibilities. Take a second to look at what's going on, and see if you can delegate it to someone else or learn to see if what you're saying yes to is really a responsibility... Look to someone to talk to about them... See if there's anyone who you could lean on or share your responsibility with... Take an extra 30 minutes in the start of your day to breathe deep breaths, listen to fun/inspiring music and dance to it, or mindfully eat your breakfast being there with every bite... Even seeing a counsellor or a psychologist could help.

Sending love to yourself, delegating work or caregiving responsibilities as much as possible to others while increasing responsibility for your own health and well-bieing multiple-fold, taking care to enjoy life's entertainments and fun things, whether it be musically, playing video games, going to VSO or other concerts, dancing parties or just putting on music at home and dancing and singing to it for fun, going to galas, being artistic in ways you like such as visiting art galleries, learning other languages or musical instrument, watching comedy movies/ comedy sitcoms on TV etc., listening to fun inspiring and uplifting or romantic mainstream music, playing card games or board games, drawing and sketching or painting, or just resting in a warm/hot bath with a cup of hot cocoa and candle light and vanilla scented bubble bath/bath foam while beautiful calming spa/fun music you like (Youtube or CD's) plays in the background on your stereo or computer. I know how it feels to feel overwhelmed and down on life, it's not fun at all: but i also know you will overcome it by just feeling the uncomfortable emotional waves as they come thru you and reducing/delegating non-self responsibilities to others, knowing that the discomfort will eventually come to pass and subside over time. Breathing deep breaths and eating fun snacks and treats you enjoy is nice too, so don't be afraid to have food you enjoy too along with healthy food/snacks; i like @Breathe's kind and wise advice as well.

is your priority. As the saying goes on the airplane, put on your own oxygen mask first or you won't be able to help others. Drop the responsibilities that have the least consequences. Also, I agree with @Breathe re delegating to others.

Try going to a Naturopath, get some genetic testing around your methylation cycle. You can change your mental state by balancing your neurotransmitters, eliminating foods that your body rejects and being more aware of the options. Don't just opt for depression or antidepressants, try looking at the root, your chemistry. Genetic testing is new medicine and it works. I was depressed for over 50 years and learned that changing my diet changed my mood. Naturopaths can help you. Seek knowledge about the fine tuning of your machine, your body.