Feeling under attack.
Amanda, YEs! That's exactly what it is, someone with gifts like ours, but who uses them to hurt people instead of spread light.
Psychic attack is just sending negative energy to someone. It could be for a lot of different reasons. For me, I've had it happen a lot from my dad because he's a narcissist and I'm the scapegoat kid. A lot of times from him, it's dark energy to keep me from seeing what he's actually like and what he's doing and to keep me infantilized and feeling small, so I can't stop him or expose him and things like that. It's really pretty sad. I've gotten it recently from a friend that asked for advice on a personal matter with her family. I could see what was going on, so I gave her some advise and she pretty much opened the gates of hell on me. Except for my dad, I"d never felt such strong negative energy before and it took days to clear. It was like screaming, shrieking angry energy that wanted me to suffer so greatly, I'd be very sorry I called her out on something that was going on with them. No one wants to be called out on stuff. I totally understand, but I didn't know she was a dark person, so I didn't expect psychic attack.
Also, your ex sounds like a perfect candidate for someone who would use psychic attack. Usually control or power and things that go along with those are the motivations for doing that to people. Those pains and things like that sound exactly like what it can feel like. I bet you have a lot of energy chording to him and a lot of dark devices from him to keep you in his power and control and punish you for trying to break free.
There are lots of methods to get rid of energy chording. Here is one that work for me. It may or may not be one that help you, but it's a start. I go into a meditative state, I don't even totally have to do this anymore. After practice, I can do it fully conscious and even sitting in my desk at work. I don't know what kind of healer you are or what works best for you so do it the way you feel the most comfortable and that will be the best way for you. Anyway, look inside and ask to see unhealthy energy chording. When you start to see it, imagine an angel or yourself or god or whatever makes you feel the most comfortable, cutting them. I imagine a sort of machete chopping them down like those thick ropes of vines on jungle trees. Watch them sever and then ask to clear them out, and watch them leave. There are probably layers of chording, so once you feel they are all gone, wait a few minutes and ask if there are anymore. Plus, with psychic attack, you are more likely to have hidden chording, you can ask to be shown those and cut them, too.
You also probably have devices. Those are energetic tools that are positive or negative. We can make positive devices to help people. An energy worker friend made me an energy device to help me because I'm so empathic. It was an energetic mirror that when people sent energy to me, it hit the mirror instead and went back to them. It sounds super weird, but it helps. Anything can be created out of energy, positive or negative or neutral. People can create dark devices like ones that make your body hurt like you said, and ones that turn your vision dark and hurt you in other ways. You can get rid of those the same way as chording. Ask to be shown all negative devices, hidden and unhidden and command the angels and guides and god or whatever you are working with, to remove them all. Then see them come up and get removed.
I hope this is helpful. Good luck!