Having too many things on your mind will drive you crazy or at least depress you. (Depression is a means of escaping too much pressure from too many negative things going on at once!)
The human mind is built only to handle a limited amount of negative pressures and thoughts. We must honor that. We must learn how to properly manage and handle that vital aspect of our lives. We must learn to manage our world and our mind, both! There is no other legitimate choice!!!
Read and learn and understand and, indeed, master: Driving Yourself To Being Crazy! Too Many Problems, Thoughts, Fears At Once!