How do I stop picking at my cold sore before it turns into a worse fever blister?

Keeping the area moisturized made the biggest difference for me, when it is not dry and cracked I am way less tempted to pick. I keep a plain spf lip balm in every jacket pocket so my hands reach for that instead.

I put a small patch or a dab of abreva on mine, having something covering it reminds me not to touch. Clean hands and a little patience go a long way.

What helped me was treating it like a habit thing, I keep my nails short and give my hands something else to do like a fidget ring. I also focus on sleep and stress since my skin always behaves better when I rest, everyone is different though so see what works for you.