It's always good to reach out and make friends, regardless if you have 2 or 20! First, I do want to say don't be too hurt by your friend not calling. I just went back to my hometown for 3 days because my sister had a baby, and did not call my dear friend who I've known for 24 years (been involved in all of each other's big life events). I was helping my sister finish getting ready before she went to the hospital, I was visiting with my grandmother who has been very ill, and then my sister had her baby. We have a ton of family in the area but I only saw my immediate family, plus my BIL's immediate family. I didn't even see my uncle's family who lives next door to my sister and down the street from my parents! I truly wish I could have seen my friend, but there are only so many hours in a day. I was able to sneak in a quick visit with her last November when I went out by myself when my grandma was in the hospital, but it just doesn't happen every time. It's not because I "can't be bothered", it's because I don't always get to do everything I want all of the time. I hope seeing it from the other perspective helps with the hurt.
I wish there was a sure-fire formula to follow to make friends, but it's really a lot of work! Reach out to other people around you at synagogue, the park, mommy-and-me classes, storytime at the library, wherever you go. Bring cookies to that family at synagogue you think you'd get along with. When you hit it off with someone at the park, say "I'd love to meet you here at the park again. How about next Tuesday at 10am?" It can take some time to find the person or people who you get along with AND your schedules are compatible AND similar life stage AND lives nearby, but it can happen, and usually when you least expect it :)
I actually live outside of Denton, so if you'd like to meet at the mall play area sometime (or park if it warms up!), message me. My youngest is 2 1/2, and it's just me and him during the day right now.