Talk to both your brother and mother first and see if you can resolve anything.
if you do decide to go to the cops keep the following things in mind.
by your own admission you started the physical fight by throwing a pillow.
by your own admission before your brother assaulted you, you may have technically committed Battery "Battery was defined at common law as "any unlawful and or unwanted touching of the person of another by the aggressor, or by a substance put in motion by him.""
You only have a witness for the very end of the fight. anything before that is going to be his word against yours, and no doubt his version of the events will have you being far more violent in your initial attack than you personally think you were. Especially since he is already claiming self defense.
you claim you didn't fight back after he came after you, but the simple fact is you already attacked him.
I'm not saying that you aren't a victim of your brothers assault, but more that it's not clear cut. No doubt you could likely get charges pressed against him if you wanted, but it's also possible that he could also get charges pressed against you if you went that route (and likely would at least try) and depending on how things played out it isn't even beyond the realm of possibility that since you initiated that situation by attacking him with a pillow that you could have a crime tagged to your name while he could get off with a self defense (not very likely especially since you have wounds and he doesn't, but not impossible)
If this isn't a pattern of abuse, it's far better to not potentially ruin both of your futures over a single fight like this. If you own the ps4 and the TV reclaim them by figuring out how to make room for them. And if this fight is going to be an issue, likely try to figure out the best way to no longer live with him, but given you are family, if this is a single incident, I would not personally recommend pressing charges, especially since it will basically make it impossible for you to have a proper family get together ever again.