Do you realize that your body can't lose weight forever? If that were the case, you could remain in a deficit until you disappeared, haha. Extremely unlikely, which is only my opinion of course.
At your starting weight, your maintenance caloric intake was 3000+ cals. You cut it to 50% of that, I am assuming overnight?
That tends to do crazy things to your body, namely your endocrine system. Once hormones get out of whack, all hell breaks lose. Your body begins to fight itself for sustenance. It thinks you are starving yourself or stranded on a deserted island, pick your choice. Either is not pleasant and your body is aware of this. The beauty of physiological survival mechanisms.
I would recommend "resetting" your metabolism by systematically upping your calories back toward maintenance. It can be a long process, with some small amounts of weight gain at worst if done correctly, but it is the only way to reverse what you have done.
Cutting calories more is NOT the answer.
And the closer you get to your "setpoint" weight, the harder it will become to lose the lbs. For most, it takes more than straight deficit dieting.
I would like to hear more about your resistance training program set up.
