Hi Mish,
I fully empathise with the situation you are currently struggling with as I have a son who regularly undergoes psychosis as a result of methamphetemine use on a 'proposed background of schizophrenia. He also denies he has a mental health health problem,
It is not uncommon for people diagnosed with mental illness to lack insight into their their condition, plus dealing with the associated stigma, grief, anger, disempowerment that can occur.
Men also have more difficulty talking about their problems and anger is often an expression of their depression.
However, you say you father has been seeing a psychiatrist "on and off " for a number of years which implies he has that he has some awareness of needing help, but what treatment regime has the psych. engaged for your father that from what you say can not be very effective if the problems are escalating.
I have had to develop coping stategies in face of my sons' erraric behaviours, even when not psychotic he is tormented by derogatory voices that medication does not alleviate, consequently pacing around the house for most of the day arguing loudly with them, demanding they leave our house and so on. There is associated rage and anger associated with his experience.
I have found for myself it is critical to learn strategies to stay calm and and peaceful in the face of the onslaught of anger and the associated psychoemotional energy. This stressor will incur a natural fight or flight response, so it is important to not react with anger, argue, be dismissive of his experience, lay blame as these responses can incur an escalation of the problem.
Sometimes it is better to remove myself from the situation, retreat to another room to find space to become peaceful, calm and relaxe breathing excercises can help as has learning meditarion/ mindfulness.
cognitive behaviour therapy (calming affirmations can be very helpful-mind over matter). Always speaking gently and calmly greatly assists. Extending unconditional love, the person is not their behaviour or their illness, so not judging accordingly, there is a person behind these outbursts possibly crying out for help and love.
Try and stay hopeful for your fathers' recovery, expecting the worst can potentially create self-fulfilling prophecy.
I can relate to the guilt experienced when a situation becomes unmanageable and medical intervention/
hospitalisation can be imperative at times. Try not to beat yourself up over this as you are doing the best you can.
Hopefully your fathers' current hospitalisation will lead to his gaining more effective help and treatment.
If you haven't already done so accessing help through carers support groups/organisations, can provide further advice and assistance.
GPs can be very helpful in establishing a mental health care plan. My own experience with public mental health is psychiatrists place major emphasis on a medication model, a wholistic treatment approach including psychotherapy and counselling can address underlying psycho-emotional issues.
I know this is dificult when your father is in denial. Don't give up, have faith that things can get better.
Love and Blessings.