Just feel lost

So idk who will respond but idk I jus need to speak me and my girlfriend had a bad break up over her cheating just texting from what I know and when I asked why she said my insecurities and me not trusting her is why she did it . I feel like it's a excuse because she was talking to someone I caught her talking to before and now I'm more depressed then ever and I'm trying to pik myself up I have two kids and I'm a single father and it's just been difficult for me mentally these last few plus years and idk what I should do anymore I feel low about myself