yes, you're booked in D1. I and D are D1 fare buckets, everything is fine.

the current offers are more expensive because there are no seats left at the discount rate you were able to get (or, possibly, there is remaining inventory but there may be conditions on that fare that can no longer be met (e.g. there may be an advance purchase condition of at least 21 days etc)). this is pretty common and why generally you see prices go up as you get closer to departure.