Advice about changes in diet. Rapid weight loss?

Hello. I started a diet in June. Instead of it being a fad, I appear to have taken aspects of past failed diets, and learnt from it

Anyway, I initially started out by cutting bread and pastry out (pizzas, chips, anything stodgy). My imagination then kicked in, and I read the backs of packets to find the foods I liked low calorie (prawns, meats, veg, grapes, chilli flavoured meals). Then if I was on a night out, I switched from cider, to vodka and soda water

I lost 4 pounds in first week, and by 2 months, I'd lost 2stone. That was my goal. I went from 20st to 18st (I'm 6ft 2, I know that's not an excuse)

Was that rapid weight loss unhealthy? I average about 1400 calories a day

It's 3 weeks since I touched 18st, and nothing more has been lost

Has my body adapted? Will I now lose further weight slowly? Is this now the healthier way of losing weight?

Thanks for reading