I found cords a bit ago, I don't have bad ones but I did cut off some old ones
so first off, it seems you can either be cording to someone or they can be cording to you. each chakra seems to own tentacles and if they reach out to someone else (as they tend to in close enough conversations or relationships) then one or both of you will cord to the other. sometimes these are one way. when I first found these, I noticed a lot on one of my chakras that's a little busted so I got mad and I cut them up, cuz that's what people said about cords. you cut them. I did this by making a sharp astral construct and then went at them (it was like a razer). Most were easy to cut, they were kind of old and lazy. One particular cord was of a very clingy ex, and it behaved as expected, and refused to string off and it took a lot of cutting, kept trying to connect, stick, make itself sinewy and hold tighter, etc. Then after I did this I realized, I shouldn't have done that, because some of those cords were mine. Whoops. I could've just realized I was reaching out to those people and pulled the tentacle back. it's fine though, they heal. Just maybe not recommended to butcher like such!
so anyway, moral is, figure out if the cord is you reaching out to the entity or it's the entity reaching out to you. If it's you, just decide to move the cord to get a feel for it being yours, then decide to pull it back (it might be wrapped on the other end, to cling on, so you have to relax it not just pull sometimes). Check from time to time afterwards that you didn't subconsciously re-attach yourself out of habit (kind of like a comforting blankie thing, or the reflex one gets when they're about to fall and grab a nearby surface).
If the cord is not yours, that could be more difficult. Like the earlier poster mentioned, what you're dealing with can vary. I've in the past sent desecrating energy at stuff to get rid of it, other times the blade trick works, etc. It's basically a problem of alchemy. You might also, after you remove the cord, need to shield (like a magical block button), and again regularly check that the cord doesn't come back when you weren't watching. This should get your chakra to start healing -- though you can also focus on that chakra and try to breathe with it, to get it moving some days after, in case it's stuck.
Since it is attached to your sacral, I would assume it's been feeding off of your energy. You might experience emotional turbulence afterwards (of a more firey sort, or sexual). You should feel a lot better after the fact though.
something else. Some of my cords or default cording in my chakras were black. In them, it was my negative expectations / paranoias, which existed for me due to past events therefore I expected them again in the future. I noticed for my chakras where I generally have positive connections, especially very positive, not only are they saturated with a color but they also glisten silver/gold on the outside. If you intend to have negative feelings for stuff, you can keep them this way, but if you want to cleanse that stuff out I should mention positive relationships that are win/win look different -- the silver/gold seems to be some kind of filter to ensure the relationship stays positive, too, it seems to me?