If you have actively suicidal thoughts, feel that you might seriously harm yourself or others, or are in the immediate throes of a mental health crisis which is stopping you from functioning, then online therapy is not the right option for you.
If you feel you can't call a mental health professional, family member or friend, then call:-
The Samaritans if you are in the UK. They are available 24hrs with a confidential and non judgmental listening service.
Befrienders if you are outside the UK. They have links to helplines across the world, in many different languages.