You are asking for an ELCS, on the grounds that:
as my previous birth was absolutely dreadful, a harrowing, terrifying and agonising experience where my son was more dead than alive upon delivery and I'm petrified of going through similar again, I'd run through the whole story but it'd take me a couple of hours to type out, every time I think about it my heart races and I feel nauseous. It's happening right now actually I can feel it thumping at my chest worryingly rapidly.
This is trauma, and is therefore a mental health issue. There is no shame in this.
The problem is that the midwife has told me I basically have no chance of being granted an elcs and the only reason I'm going to see the consultant is so that he can probably refer me to a mental health midwife, which personally I find insulting as it suggests that I'm over reacting about the horrendous experience I had before.
Lots of midwives hold this view. Its wrong and not reflected in NICE guidelines. It is completely appropriate and in line with NICE guidelines to do this. At this point you should be offered counselling. Note the word offered. You are under no obligation to take it if you do not want to. And if after this you are still not comfortable with a VB you should be granted an ELCS.
HOWEVER, and this is a big however, you DO NOT have a right to an ELCS. You have a right to the most appropriate care, based on your medical need though. Medical need INCLUDES on mental health grounds.
The NICE guidelines currently, are strongly worded, to favour women who request an ELCS on similar grounds to you. Hospitals are not obliged to follow them, but they do provide a very strong back up to any argument you have. UNFORTUNATELY, there are a number of hospitals who currently have a 'blanket ban' on maternal request ELCS, and they are wrongly classing requests on these grounds as being maternal request rather than based on your mental health needs.
There is a general attitude about trying to put women off following through with such requests for this reason. Rather than try and offer support, there is, in some places, HCP who try and deliberately undermine and belittle women's feelings and suggest they have 'no chance' in getting an ELCS.
In some places, this may well be true, due to the above mention blanket bans, whilst in others its just not.
The good news, is that, if you are serious about this, and feel this is the way ahead for you, then if you pursue it and are prepared to fight and understand this may drag on until late in your pregnancy then the chances are you will eventually get an ELCS. Equally you may be surprised and have no trouble at all. Its a real lottery at the moment, I'm afraid. I've been on MN looking at threads like this for several years. In that time, I have seen only 2 occasions where there hasn't been a positive outcome and I've seen a LOT of similar posts. (In one of those, the lady in question switched hospital and DID end up with an ELCS in the end. In the other, the lady was granted and ELCS, went into early labour and then had a very difficult consultant who delayed things until it was too late. But these are exceptional.)
However, I would encourage you to engage with the mental health team. The team at the hospital I am at are extremely good; the consultant midwife I have seen has a policy never refuse a request. They have an approach of trying to build relationships with women and finding out exactly why they want an ELCS and trying to address each issue and see if there are alternative ways to provide reassurance. In cases such as your they have a track record of getting women to build up trust and feel confident enough to go through with a VB after all without pressuring them. Many others don't change their minds, but feel more reassured because of the non-judgemental non-pressured approach they have. My point is to see what they have to offer as an alternative at the same time as pushing for an ELCS. You can change your mind at any time, an ELCS is ultimately NOT right for everyone. There is no right or wrong in this, just a right or wrong FOR YOU.
I am personally having an ELCS on the grounds of mental health. My circumstances are different - perhaps less in my favour than you have - but I have had success. It is NOT a maternal request in the definition that you will see in the newspapers. It has been made clear that my request, is a sensible one based on my personal circumstances and that they view it as medical need. My experience has so far been very positive and easy. So its not always a battle.
Good luck.