I messed up

Tonight I hate myself as a person and a mom. I’m a step to mom to 2 teens. They live with us full time, per their choice for almost two years now. They’re my whole world besides my baby. I do everything for them and more. We have an amazing relationship that I’ve worked so so hard on building after going through hell to get there. Their mom despises me. She is the nastiest person ever and acts like she’s the best mom and human in this world. She does nothing but tear me down. She texts my husband constantly with complaints about me saying it’s coming from the kids. Then we confront the kids and they say it isn’t true. This weekend it happened again and I hit my limit. I broke down in front of the kids. I said something that upset my step daughter a week ago and instead of coming to me like we encourage she went to her mom (yes she has every right to talk to her about things but we ask if they have an issue with us to tell us first so we can fix it). Then her mom went to my husband and twisted the whole story. We read the text to the kids and they said it was totally twisted up and exaggerated. I lost it. I cried and cried and said how tired I was of this. How hard I try with no recognition. I said sometimes it made me want to leave because it’s so exhausting and damaging to me mentally. I told them it’s so hard to believe anyone because I don’t want to accuse anyone of lying, even her. She’s made my life hell for 3 1/2 years. My husband was so angry at me. I always keep it together and try my hardest but I couldn’t last night. I wanted to absolutely die. An hour later my step son texted me screenshots of texts to his mom. He stood up for me. They’ve never done that. Especially him. He treated me like a mom. I apologized to them and said how much they mean to me. I made them their favorite snack and brought it to them. We talked and laughed. I still feel horrible. My husband and I made up. But I feel like the worst person ever still.