i got slapped on my ear by gf really hard and it caused ringing for a hour or so and hurt badly
That ringing is what we call tinnitus. But that kind of tinnitus usually wears off on its own once the ear has healed and the auditory system has calmed down. The pain may indicate an injury, like eardrum perforation.
2 days after the slap couldnt hear then my hearing came back to normal
I'm not a medical doctor but this seems like it could have been raptured eardrum. Without a working eardrum you can barely hear anything. But a raptured eardrum usually heals on its own. It depends on the severity of the rapture. It may need immediate medical attention. It seems like yours has healed after 2 days.
then i started hearing a buzzing noise in the ear that got hit and i hear it all day when its quiet or silent
That buzzing is tinnitus as well. Tinnitus can manifest itself in many ways. Basically any kind of sound you hear without an immediate external sound source is tinnitus. It seems like yours is a minor or mild tinnitus. This may stop once the auditory system has calmed down if you give it time.
went to doctor and doctor said that i didnt have a infection or hole in eardrum that i have dry blood
No infection? No eardrum perforation (hole)? But yet you have dry blood? Dry blood?... what does that mean? If there are traces of dried out blood in your ear it may indicate you had perforated eardrum which has healed on its own. When did you see the doctor? Right after the injury or after those 2 days of healing?
When will my ear heal when will buzzing go away?
It seems like your eardrum has already healed. Assuming you had a perforated eardrum! If you give it some more time the tinnitus sound may go away on its own. Then there is also the possibility that it may not go away, if the injury is sever enough.
And what did he mean hy saying blood is in my ear.
As stated above, it may indicate that your eardrum was perforated and it has healed on its own.
What kind of doctor did you see? I would recommend that you go see an ENT ear specialist. You should also do a hearing test. It may seem like you have "normal" hearing now, but it may not be as normal as you think. Just to be on the safe side, do all the necessary checkups.