So my older brother who is 23 the eldest of 4 kids has developed schizophrenia is in need of help but won't come to see a doctor even just a GP. He has been involved with drugs for quite some time not heavily involved but socially.
My brother and I have a close relationship and I feel as I am the only person who he trusts anymore, since he has lost contact with nearly all of his friends.
He started to show signs of schizophrenia at the time when he and his ex girlfriend broke up after a 3-4 year relationship. At the time she moved into the family home where my brother and his girlfriend, shared a house that is detached from the main house. All seemed to be fine during the relationship and my brother started studying psychology, and got a job working for my parents. Not long after he started he and his girlfriend broke up, she started yelling and punching my brother and left him with no money and half of his possessions gone. Around this time (not long before they broke up) is when I started to notice some signs such as conspiracies and believing that his ex girlfriend is some sort of god figure an angel or something, describing her as a lady in a white dress. Ever since then my brother has seemed to be depressed and that was about 2 or 3 year ago. He has since found himself another girlfriend and they have been together 1 year or so. In this time my brother told her some things about his ex girlfriend, such as she fed him ecstasy and put some weird thoughts into his head. But during the 1 or 2 years he started getting heavily involved in the conspiracies. Some of the conspiracies where thinking that everyone knows a secret that he doesn't and we are holding it out on him. Then he started telling my sister and me that god wants him to save the world and that he has to get rid of his best friend (of nearly twelve years), because he is going to try and stop him from saving the world. Then he started describing his friend (the one who was going to stop him) to me as some sort of demon, or satanic figure.
This type of talk went on for some time but then eventually died down. He got a job again working for my parents and all seemed to be fine. But lately is when he started hearing people say things and developing these conspiracies again, and quit his job back to sitting in his room all day staring into space or listening to music. He has herd my mum and her mother say that they were going to kill him, then the other day he started a conversation with my sister saying "who do I have to shoot first" and nothing else. He seems to almost have a split personally where he is normal or starts sketching. He doesn't look the same anymore always having worried expressions on his face and in his eyes, barley socializing or even talking to anyone.
My family, his girlfriend and myself are extremely worried about him and want to get him help. We have tried addressing him with the issue last night saying, we have booked a doctors appointment and all he has to do is go, we don't even care if he talks to the doctor we just want him to go. He started saying that he doesn't need to go and he is fine. I even offered to go with him seeing as I am the closest person to him at this time, and he considered it. Later on I seen him again in the kitchen and started talking to him about the doctors saying that they have helped me and the worst thing that can happen is nothing he can only get better if he goes with me. I said that I will go with him tomorrow and we can hangout afterwards, it seemed to convince him and we both went to bed after talking for a little while. I went down to collect my brother to come to the doctors this morning and he as still asleep so I went down another 30 minutes later. When he woke up he said that he is fine and doesn't want to go to the doctors to talk about problems that he doesn't have, he denies that there is a problem. I talked to him for a while trying to convince him but it didn't work. Me and my mum went to the doctors anyway to see what where the options in this situation but the doctor just being a GP couldn't offer much advice except for his personal experiences with schizophrenic patients.
From what I have gathered my brother started of with the depression from the brake up and the thoughts his ex girlfriend gave to him slowly developed into paranoia then the drug use brought out the psychosis leading to schizophrenia, plus the amount of time he has to himself (spending everyday in his room by himself) to over think things. I don't know if I am right but that is just what I think, could I be right?
So basically I was asking how I should deal with my brother and try to convince him to come to the doctors and that there is a problem that we need to address before we have to resort to the mental health department coming to the house and taking him to the hospital. Is there special tactics I should try to undertake when I am dealing with this situation things to avoid etc?
Any help will be greatly appreciated.

plus i dont want to get the mental health involved but if i have to will my brother blame me and will he forgive me?