I need advice/help

Hey everyone. I apologize ahead of time. This is going to be very long.

Let’s start with my baby daddy. When me and him got together we got pregnant pretty quick. He cheated on me. Never really cared for me. It got to a point I was sitting there thinking is he lying or am I just going crazy and freaking out for no reason. He led me to believe I was crazy. Anyways we have our son. Our first kid. I was 17 when I gave birth. He was 20. Anyways. We end up breaking up when my sons 8 months old because our relationship just got cold. He had no emotions. Spent no time with me and wouldn’t even watch his son (never was really hands on at all) wouldn’t even feed him food. He said he had a baby food phobia 🥴 anyways I start dating someone I went to high school with and he’s honestly god sent. I notice my mental state isn’t doing very well and still isn’t but I really can’t put a finger on what’s goin on with me. I feel like my brain has a fog. I can’t remember anything I’m a very emotional person now and I honestly don’t know what’s wrong (if any of you can give me some advice maybe doctors/medications/maybe therapists to help?)but anyways I start dating my high school friend and it’s been 2 years now. Baby daddy walked out and signed over his rights. My son doesn’t know his real father he sees my now fiancé as his daddy. Which was by his own choice. Never forced. And I want another baby. But here’s our problem. I don’t think he can get me pregnant. His dad had issues and only had one kid his whole life. And it’s been a year and I can’t get pregnant. My best friends called us yesterday to tell us they’re pregnant and I just can’t help but to cry. I got pregnant so easy the first time but now I cant. I need some support yall 😖