How can I help my girlfriend[F19] and fix the issue surrounding my[M20] friends?

For some background, me[M20] and my girlfriend[F19] have been dating for 6 months. We met at my old job and started around the same time but only started dating in May. Sorry for any typos and the long sentences, I am typing this late at night.

There have been some incidences in my relationship where I have upset her and have hurt her feelings greatly. A month into the relationship, I had a falling out with my best friend and had to end the relationship. I was sad at losing my friend and didn’t have many friends beside her but I started becoming closer to a work friend because I confided in her about it. Me and my girlfriend were going to hang out after I got off work but she canceled. So I decided I could ask my friend to hang out instead. Then my girlfriend said she could hang out again and I told her that’s okay, I just have to cancel my plans with my friend. She was upset that I made plans quickly and felt that I chose the friend over her and didn’t want to hang out anymore and wouldn’t talk to me. Yes, I know I made plans quickly but I was just excited to hang out with a friend since I hadn’t in a while but I feel like I made a mistake here.

One time, my girlfriend came to pick me up after work and I walked the same friend to her car cause we were heading the same direction but I didn’t chat or anything, just said goodbye and walked away and there was no issue then. Cut to last month, it was chilly and me and my girlfriend were closing together and I did not have a jacket and my mom was parked om the other side of the parking lot from employee parking. I kissed my girlfriend goodbye and ran to mom’s car because I was wearing short sleeves and it was about 30 degrees. Later on, my girlfriend was upset that I didn’t walk her to her car when I walked my friend to hers and I apologized and told her that I did not realize. It was important to her and she was very upset no matter how much I apologized and she accused the friend of being my work wife and said that I’ve called her that but later admitted that she knows I never said such things. Her saying that made me reflect on my friendship with this coworker. I have only hung out with her twice after work, for about an hour each. We do not text outside of work and I have no feelings of attraction for her. I have always had platonic female friends because as a feminine bisexual man, they are more accepting. I have never cheated or had weird relationships with women or even men that affected my partners and this is my first relationship with a woman. I am anxious to be in contact with this friend because I don’t want her to be worried that anything is going on when there is nothing, I love my girlfriend and my friend has been with her boyfriend for 3 years and he is a funny guy who I also talk to and care about.

The last incident happened tonight. I have a highschool friend who I have reconnected with because she worked at my old work. She called me tonight to catch up and while we chatted, my girlfriend called. I texted her and apologized and said that I was talking to my friend and we could call once I’m done, it was a short conversation. She was very upset and texted me that I always miss her calls which is true, we FaceTime on Google meets and my Google meets is bugged so I never get a notification when she calls but when I miss them, she texts me and I always call her back and apologize for my Google meets being broken. She was very upset still and no matter how many times I said sorry I could not console her. I just want to know if I’m doing something wrong and if there’s anyway I can fix my behavior so that these incidents don’t keep happening because I care about her and want her to feel secure in our relationship but I also like my friends and I know that them being women is weird to her and her family. It’s not like I only have friends that are women but having any at all seems like a weird thing to them which is understandable.

TLDR: I make girlfriend upset with my actions surrounding my friends and I want help repairing the damage.