Wanting to change little things about your partner, wondering if you fell into bed at the right time, wondering about feelings, worrying that kids will get too attached... this is all perfectly normal adult dating stuff. Just keep being honest and compassionate and take care of yourself, and I think you will be just fine.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.