I have no clue when I got this question but I’m answering now lol. Hope I’m not too late!
Yes a 1000 calories deficit can be dangerous. Losing more than one pound a week is not recommended unless you are obese and your weight is harming you presently. You’re only 150 pounds, unless that bit if extra weight is currently causing health problems you should aim for 1 pound or even a half a pound per week.
This makes it easier to adjust when you reach your goal. As you reach your goal you want to make the deficit smaller. Like you said upping 1000 calories sounds scary. So you do it slowly.
That also allows your body time to realize this isn’t extra food it’s what it needs. So you won’t gain so much when you go back to eating a normal diet.
So my advice is to eat more have less of a deficit. Do it slowly if you want, you’ll still lose. It may be slower and you may gain a tiny bit, but it should come right back off. As it’ll probably just be water weight from the extra substance in your body.