With regard to the NI contributions, you need 35 years of full contributions to get a full state pension.
I'm 57 years old and have 42 years worth so far if that's any help. I gave up work to be a SAHM for 12 years of that. At the time I went on maternity leave I was at 29 years contributions so I just made a lump sum NI contribution to make it up to 35 years. Since then I started my own little on line business and, even though I didn't pay tax on that, I kept up the NI contributions each year which has taken me to 42 years.
Just check what you're currently on as far as your years contributions is concerned and keep an eye on it so you can make additional payments if the government change tact.
As far as giving up work is concerned and feeling lazy or that you shouldn't do it. There's lots of things you can do if you have the means to support yourself.
Volunteer once Covid is under control (or even now if you can deliver prescriptions, sew for the NHS or help with a newsletter for a volunteer organisation). Start a little business. If you're a craft person you can start a business on Etsy, NuMonday or Folksy. Price it right and use social media and you could bring in a bit of cash especially at Christmas time. My business goes mad then. I started my business when I had a 5 year old and mum with dementia - it was hard to keep 'me' in mind with all the caring I needed to give. The business kept me sane and gave me my own money (albeit a small amount). I now earn almost as much in a good year with my business as I do from my part time job.
Could you do a bit of retraining or study for an OU qualification if it's more the idea of 'keeping busy' that's important? Get a part time job that actually suits you. Are there things you enjoy doing? My friend is a keen gardener but was working in an office. She's now working 15 hours a week at the local family garden centre and absolutely loves it. She doesn't earn anywhere near what she used to, but her mortgage was paid off and her stress levels were rising with all the office politics so she jumped ship. She's got enough coming in to cover her expenses and she's happy.
Good luck in whatever you decide to do. Just think outside the box, check your pension and your rights regarding benefits that may be available as you get older and do your sums!