I am so sorry you are feeling down, and you need to seek some help. Please don't buy anti-depressants yourself- but go and see your GP.
There are so many different kinds of depression. From mild, and reactive depression (linked to an event, bereavement, diagonosis, or perhaps even, the news ..) and all the way to severe- and they all need a different approach.
If you can't get an appointment, as I am aware it it snot easy at the moment- make an appointment to see the Chemist's in private and discuss what is happening.
hugs take care, get help