I really just need to vent.. I have no one to talk to. Is my ex a loser?

I literally have no one to talk about my horrible breakup that would understand what I’m going through. I just keep it all bottled up. So I wanted to see if anyone understands my pain. And if my ex is actually really fucked up as he seems. It was a 7 year relationship/engagement. We lived together for 5 ish years. It was very serious and we planned on spending forever with each other. He was 25 living in his dad’s basement when I met him. I dragged him out of there and helped him have a better life. Then I was thrown away like trash once he didn’t need me anymore. I don’t wanna get into the entire story of our relationship because that would practically be a book for me to write. He broke up with me 4 months ago out of nowhere. I did notice him being off like the last week of our relationship. A new girl started at his work and he seemed off since that happened. A couple days after he broke up with me he went on a trip to Columbus to see his father. Come to find out he lied about the entire thing and actually took her with him and they went to the zoo. While they were driving there he texted me love bombing me saying he missed me and wanted to make things work and he loved me so much. He got home and basically did a 180 saying no I don’t want to get back together. That fucked me up mentally so bad. Once I moved out he went full fledge into hanging out with this girl. She’s pregnant with another man’s baby btw. And does not seem like a good person. He said she used other guys to get money. And smoked while she was pregnant. Here we are 4 months later and he just put in a relationship with this girl on his social. She just gave birth recently. I absolutely lost it. Thinking of him helping her out with a baby makes me want to vomit. Because he was suppose to be my forever. Now I feel worthless because he’d rather be with a pregnant girl and raise another man’s baby than be with me. That just makes me feel completely worthless and like scum. He would rather be with that than me. So anyway I’m a complete fucking mess. I know I’m like everywhere writing this but that’s exactly how my mind feels. Everywhere. I feel so hurt and betrayed. I have no idea what to do with myself. I feel like such a loser and embarrassed still being heartbroken over this breakup. Does anyone else think it’s totally fucked up of him dating her? It’s like he broke up with me knowing he would probably end up having feelings for her & they would date. It’s eating me up inside knowing they could be together forever. How could he have these feelings for someone only 4 months after leaving me? He was practically obsessed with me our entire 7 year relationship. I just need insight from other people on the outside looking in. Please tell me if I shouldn’t be worrying over him if he truly seems like a bum. I need to hear it.