Yes I'm a beta and I need help from you guys here's the situation

A year ago I got a gf, we were very close for about 2 months then things started to kinda plateau. She was slowly trying to get away from me as I had put her on a pedestal I didn't react to her mistakes. The started to reply me after 5-10mins on each message. Something didn't seem right I asked her she told me that she was confused with 4 guys including me. I knew those 3 guys would leave her so I sticked to her like a fucking disgusting shit. And that's what happened fast forward a month we decided to take a break(it was her decision and I agreed to it), since we were on a break she started to check out other guys and shit. Then she decided to breakup and since she liked me a lot she asked me to be with her as a friend. As a retarded beta I sticked to her for a year then I found you guys. I came to know that I was a complete retard so I told that I don't wanna talk to her again. Fast forward 2 months I recieve her text..... Please tell me how should I respond her??? Previously she placed me on a priority with 4 other dudes. I swallowed my pride for her..... I'm not putting her on a pedestal and I don't even know what to respond.... Please tell me what should I do?