How to forgive someone

Me and a friend got into it pretty bad. It is a long story but she basically disrespected the f*ck outta me and I took up for my self. Ppl that were there can tell you she was disrespectful. But, I’ve been trying to become a better person and change for religious reasons. So I text her apologizing for the things that I said in response to what she said. That I should’ve kept my cool. She responds with just “I appreciate it” but did not apologize back and I’m having a rough time getting over it. I’m trying so hard to forgive but it’s hard when they aren’t sorry for what they did. How do I forgive… completely.