TDEE BMR Help for me please?

RIght been eating pretty near my net of 1400 cals for 3 weeks or so and i've lost 3lbs (woop)
I've started exercising more now so my TDEE and BMR should have risen I think? A little confused over all.
I've used a few sites and with the exercise its advised BMR is now 1800 and TDEE is 2825 so if im right, if i want to lose two pounds a week id be eating 1800ish a day?
Could someone explain it to me please?

im 21
219lb
5ft 8in
and exercising roughly 30mins one day and 1 hour the next alternate so average at 4.5 - 5 hours a week plus one hour dance on a sunday. so 6 hours a week.