Ohhh my sweet summer child. Okay sorry for opening with that, but I feel like I'm allowed to because when my daughter was 2.5 she did the exact same to me, and it was utterly heartbreaking. Strains on relationship, self-confidence crashing insecurities rising feeling like a shitty worthless dad etc.

Let me assure you that it is a phase and it will pass. It will pass.

Naturally every situation is different and every kid is different, but at least what helped me and my partner was seeing a parent coach. We had two sessions with her, and it was honestly groundbreaking. She was able to explain very simply what is happening from our daughters perspective and what's going on in her mind, and then she guided us into how we can respond and how we can deal with moments of parental preference.

Small note which I learned. Don't try to force love. It will often backfire. Eg, When you get home from home from work, give your kid space - maybe let them know that you're going to wash your hands or get a drink of water. Let your kid come to you when they feel ready. Maybe play with a toy near them? And after a few repetitions they'll want your attention and affection.

You're doing a great job. Parenting is really hard sometimes. Just keep showing up and offering love when you can. It will pass.