Wait for two minutes before contacting her. After the two days, contact her preferably through text. Let her know that you have reflected of your attitude/behaviour (you've thought a lot about it). You have noted it is negative and you intend to change it. Ask her to give you another chance. Let her know you will not contact her for a few days (1-2 weeks) so you can work in changing your negative attitude. Let her know you don't want to lose her since you love her a lot and that the breakup has shed light on how repulsive your attitude is. During the no contact, work towards your attitude in correcting it. If need be, seek a professional counselor and let her know so. She needs to know you've changed because I do know she loves you.