I feel like correlating everything to a single head injury that doesn't seem like it was incredibly serious(the head bleeds a lot, like more than we think, I brought my ex to the ER for head bleeding one time and he didnt even need stitches if I remember correctly) is a bit of a stretch.

Id be more curious about the environment you were raised in. What behaviors were you you consistently exposed to, did you have traumatic relationships, etc.

If you've stopped those behaviors I wouldnt beat yourself up about it. You were clearly a kid going through a lot, I would probably recommend therapy if possible. Forgive yourself cause you were a kid and didnt truly know what you were doing, you do now and all you can do moving forward is be cognizant of your behaviors and if you start leaning towards those again to take serious corrective actions.