I hope that you can persuade him to go to hospital, if you think this is the best thing for him. You may want to speak to his mental health team, with a view to seeing if they can come up with a care plan for him. If he is considered to be a danger to himself - ie not taking care of himself, refusing to take meds and becoming suicidal, they might actually section him. As alarming as this might sound, it would actually be in his best interests and ensure that he gets the care that he needs.
What you mustn't do is allow yourself to be engulfed with feelings of misplaced guilt. You have done, and are still doing, all that you can to help but at some point there needs to be a boundary for the sake of your own emotional wellbeing. Having therapy for yourself would help you to process your thoughts and feelings, and provide a sounding board for you, because you will need support in this too.
In lots of ways watching a person you're close to suffering from severe psychiatric illness is like a bereavement. There will be a sense of loss for the person he would have been if he had not been ill, and loss for the life you would have had together. Therapy can help you to process this.
Please try to ensure that the quality of YOUR life is as good as it can be in the circumstances. It isn't wrong to seek some enjoyment from life if you can. This would provide a buffer for you, and ensure that you remain well adjusted, with a balanced focus on life. It would also be good for your child too. Finding pleasure in the little things, such as days out for you and your child, and meeting and socialising with people would help you to retain a sense of optimism and adjustment, and help you to retain your sense of identity, which is important. Being a carer can often leave a person feeling that they've lost all sense of self.