Hi Sarah. Welcome to the Horse Forum.
I am afraid that you are missing everything. This horse needs a competent leader and trainer and not a friend.
If it were my problem, I would put her in a small, sturdy corral. If you don't have one, build one or make one from sturdy panels. [I do not ever use my round pen for a corral. It really messes up the footing and it does not have any corners.]
Then I would get a halter on her any way I could. I have used a stall, bucking chute, a stock trailer or roped them when there was no other way to get it done in a timely fashion. Then, I would work with her and when finished, I would turn her loose in the corral dragging a 15 foot rope. Catching her with the rope should be no problem.
A person that knows what they are doing can use a round pen to get a horse to come to them, but I have never seen this technique taught on the internet. It takes a real live person that knows when and how to 'read' a horse and they 'approach' (drive) the horse at the appropriate time and 'retreat' (draw) the horse at the appropriate time. Timing and 'feel' are everything.
If you catch this horse by picking up the dragging lead-rope, you can do the same thing. The 'approach and retreat' method there is also the easiest on both handler and horse.
The main thing you need to learn -- no matter what method you try -- you cannot back up or offer release at the wrong time. I suspect that is exactly what you have done to make her worse now. Timing is everything and you can't learn that off of the internet.
Even a feral horse that has never been handled can be gentled within a week and can usually be caught anywhere within a couple of weeks. Remember, a horse needs a competent leader that they respect and look up to. From that relationship comes trust. Not the other way around.