Feeling lonely 😞

So I’m a single mom with 3 kids. I had my Fallopian tubes removed after my son. I have been single for the past 1yr and a half. I love the independence and being able to do what I want without explanation. But lately I’ve been feeling extremely lonely. I don’t look into a relationship to define my happiness. I’m pretty certain I will be single my whole life. Because who wants a woman with 3 kids and can’t have anymore. In the beginning I was open to a relationship but after a while I noticed men were more interested in the fact I couldn’t get pregnant than knowing me. I’m becoming a very bitter woman and I’m becoming more and more lonely. I don’t know what to do anymore to get over this feeling!