No problem. It really annoys me the way they think people will just give up.
I now regard the appeals as the decision makers and the MR etc as just a step in the path to an award.
Make sure you fill in the form promptly as there is a time limit - maybe a month- and it gets the ball rolling.
You can just simply state your reasons and if you want to go into more detail you can write a statement of appeal- there is a guide online but basically liek you did in MR refuting their mistakes.
I actually found it quite cathartic the thought that it would actually be read by someone properly etc.
Then, what happens is the appeals orders the DWP to copy over all their paperwork and looks at that and your appeal info in order to grant (or not) an award. This takes some time, I think there is another month or two the DWP has to provide this.
Then, after this time you also have another month or so to provide any further info which may help in support. So, for example a letter from a friend or partner about what hep you need, a letter from the GP or as you mentioned a copy of a consultant's letter or pain clinic letter- anything which helps.
It is really worth doing- also if the DWP do ring you and 'change their mind' be aware you can discuss with them the terms. I found they 'realised' I had a good case and didn't seem to want to argue the issues when it came down to it!
So, I went from nothing to a 5 year higher level award which is now in it's 4th year. I had previously also done a paper appeal back in 2016 and my reasons for not attending in person then were like you- depression and anxiety.
I simply stated in the appeals form I was requesting a paper appeal as attending would make my mental health worse. But that they could e.g. contact by letter or phone if they needed to.
It really felt on both occasions the appeals were much better to deal with so please don't let it put you off. I often see people say online that they couldn;t face appealing etc but it actually can be better than the MR stage / DWP.
I found appeals were also responsive to deal with, unlike DWP - you can contact them and ask for the progress, they actually photocopy everything you send them and send both you and DWP a copy, the DWP has to respond to them within a time frame so you don't get the endless faff with the initital stages of a claim.
I do hope all this is helpful, oh also beware services online who offer to help with appeals etc for a share in your money once you win. there is nothing stopping you doing this yourself.
Oh, also another helpful person with DWP / PIP / appeals, I found was my MP's office. They were brilliant when DWP 'lost' by successful appeals decision (this is another thing they do btw) They have people who liase with DWP as well.
best wishes and let me know how you get on