EMB-175 Flight Attendant reported the gate agent opened the main cabin door before it was disarmed. The escape slide did not deploy.

Narrative

I was distracted during the door procedures. It was taking a long time to get the ramp to the aircraft. passenger needed to use the lav. another passenger was talking to me. i missed it when the ramp actually was close and the gate [agent] opened the main cabin door. FA A called to say we didn't disarm the doors. I was shocked at this for myself as I pride myself in correct procedure. I apologized; and asked her to disarm the doors in the aft; as I disarmed the galley R1 door. I did not mean to sound aloof about the seriousness of the door ; but since it was from the outside ; thank god...there was no slide deployment. I talked to her about needing to do a report; and wanted to know if she would feel safe flying with me ever again. She didn't answer; shrugged her shoulders. the next two flights were uneventful; and I felt we had left the trip under good relations. She did a great job; calling me right away.I was trying to make sure I waited until the ramp was close to the door. their weren't that many people on the flight; only 32 so it was one of the more relaxed; chatty flight with lots of sleepers. I was tired. My procedure was interrupted as the ramp wasn't close in a timely manner and I was tired. My body clock wants to wake up at XA:30; even on my days off with the XC:00 am and XC:15 am show times. I was extra stressed that week considering a family picnic I was invited to attend that included opposing views and a close relative that recently moved with marital; family; health and wellness issues that I was trying to support.I am trying to pick flights with a later show time for my health. I have invested in a new natural vitamin supplement. Chatting is never good when you need to focus. When the passenger used the lav; I needed to start completely from the start of door procedures and stay focused on the view port window on the main cabin door or not allow the use of the lav until the door is open. I'm also having to distance myself from my relative slightly as she isn't in a place to get counseling; take steps for herself; and refuses to get medical treatment; and pray she comes to recognize this on her own so I can separate family from work in my mind.