Hi there. You should never apologies for writing anything long, people who can't read anything long in a contract based society are in for trouble further down the line. :P I have also written you something long so long infact I had to break it in two.
You have basically been fobbed off that much is obvious. It is also entirely wrong to have been put on a drug you expressly rejected. You have every right to reject medications on the grounds of weight gain. Are obesity or diabetes in your family? If so and you ever need to reject medication due to weight gain, mention those facts. It will make them less prone to viewing you as not wanting to help yourself. An unfortunately common mentality these days.
Sadly the NHS has been bastardised into becoming target driven and is in the process of being destroyed for ideological reasons. It may as well be a hospital built in a Hollywood lot. The facade is there but there is very little beyond it. It is why accessing anything is now at the worst state it has ever been throughout my entire career. It is a flawed system in what it offers, seeming to favour intervening when the person is past broken. Instead of providing preventative supports outside of a hospital environment in the first place. It operates more like triage these days; than any kind of comprehensive help. It for the most part offers a short amount of CBT and since that has become a cult of sorts in how amazing it is! (And cheap.) If it does not help you it is common for them to simply turn round and blame you for not wanting to get better. It is utterly absurd.
It was pretty common to have suicidal clients who desperately wanted help. However, there is a warped catch 22 at work. That if you are asking for help you are actually viewed as at lower risk. So less likely to get that help. After being dismissed so long those same people unsurprisingly give up. Up the ante or make attempts on their lives and if they survive, now get the help they no longer want and are rightly hostile and combative towards. This scenario played out so often it was honestly depressing. We even had a morbid name for it born out of gallows humour. I won't repeat it though because it is very crass.
This is not a route I would like you to go down personally, so let's tackle this sideways and exploit existing systems in your favour.
What follows are suggestions only. So please view them as such and not me telling you what you absolutely 'should' do.
My First suggestion would be to look into your local mind.
https://www.mind.org.uk/information-support/local-minds/
Mainly because they will know in detail what is in your local area. That may well be supportive. Unfortunately how comprehensive your mind is in your local area is sheer chance. Some mind centres offer their own internal therapies and have advocates available others are just a sign posting service. The only way to find out is to contact your local one.
The other method of going sideways is to get yourself a counselor and press them into helping you get a diagnosis. They basically can write you a supporting letter eventually. Because, sad to say if you are alone your easy pickings to be fobbed off so you don't wind up on the books. But if you have an advocate and written words of a counselor you begin to be viewed more seriously. Probably because advocates and counseling firms have some legal clout. It is ridiculous it is this way but sadly that is the truth of it.
Should you in future get another assessment I would advise against going too deep into suicidality and using words that sound like you want to die. I know that is odd. Instead keep it focused on the disruptive aspects of hypomania. If you do need to talk about how suicidal you are, try and employ language that implies suicide is some sort of stalking monster that you don't want to be eaten by. Instead of telling them I want to die, as if that is what you want. Because in their mind if you are sat in front of them telling them that, they may well be thinking, well why are you sat here then? Its ugly but it is what has become these days. If you explain it more as a threat that you don't want to succumb to, use how you are a mother and don't want to leave your kid behind, it takes on a different feel then and they may be more accommodating and less judgemental. It irritating you have to exploit language and psychology this way but it is what I have seen that works. Basically getting them on your side instead of dismissing you.