Why Gel Nails Do Not Stick to My Natural Nails?

I have tried DIY UV gel nails couple of times but each time the gel nails do not last long on my natural nails. I have removed the natural oil/shiny on my nails by filing the surface and applying the primer. I cure the gel on my nails under the uv lamp-box. And not forgetting to remove the cuticle too. However, the gel does not stay more than 2 days on my nails. I can easily remove them by peeling, let alone to last while doing my routine work. Help! Why is it the gel nails are more lasting by doing in the salon? Did I miss any steps?