It's hard to describe what I did that actually fixed it. I did the normal trying to install the firmware through itunes, got absolutely nowhere. Nothing but errors. Read online people saying to uninstall and reinstall itunes, amongst other random stuff. So I moved to my laptop and started doing it there, even using a different cable. It didnt fix it but it seemed to give me different number errors. In the end I flashed it using redsn0ws option. The first 3 times didnt work, but it finally understood what I wanted. So I think not doing it through itunes did the trick.
However any time I tried to jailbreak it from the screen where it demands a sim card, I'd somehow completely destroy the phone in some way, and have to try and reinstall the custom firmware again. Right now I think I'm on 4.2.1...or maybe 4.3.1.. I dont know. One of them. The phone before was unlocked but I guess its been overwritten as the only sim card I have that fits is from a different phone company. It worked in it before. Not now. So I'm in that moment of I THINK I fixed it, but I dont really know 100% without getting past this stupid sim card screen.
I'm going to go ahead with that adaptor and see how I go.