Get that woman back. Take her to couples counseling and start a family.
You have time to find another person. But 18 years is a long time to co-parent. If the relationship doesn’t work out you have to hope yall are on the same page on school, extracurriculars, religion, holidays, working through growing pains the kids may experience, potential medical issues, in-laws and extended family… it’s a lot of headaches if you aren’t on the same page. Because parenting is everyday and kids grow into their own little personalities with wants and needs you would never imagine. It’s incredibly rewarding but also very hands on.