you have three key groups who could be provide funding for your charitable trust:
1/ The Govt should always be your first priority in regards to funding a charitable trust, and in particular the Health Ministry in your case has a material budget set aside for mental health. I would talk to any contacts you have in Govt or you local MP.
2/ The bank’s are providing $500k bank loans for all businesses affected by Covid19, you will need to have a business plan and supporting financial documents (financial forecasts) to show that your trust has the ability to repay the $500k in 3yrs time.
3/ The third group would be high net wealth families/individuals who believe in the trust and would like to donate money to your cause. To reach out to this group you would need to have a document that explains exactly what your trying to do; effectively a business plan. Their are organisations who can distribute your business plan and help you raise equity but that comes at a cost of 6% of equity raised.
Long story short, when you are looking for funding you need a business plan or a similar document that explains to all the potential funding parties what you are trying to achieve.
I hope this helps.