what happens when your charged with a serious crime like sexual assault?

so recently I was caught doing something wrong I met a women who was a drug addict and I thought we were friends until things got bad I hugged and kissed her and I didn't know she had a boyfriend so basically I was set up her boyfriend is a man in his 50s and he threatened to kill me with a baseball bat so how long will I be in jail and also will I get bailed I feel like I should turn myself in this happened yesturday.