Yep, I understand! We all have to find what works for us, and I think trying 1600 (or even 1800) calories a day would likely be sustainable for you and lead to (hopefully) regular weight loss.
Patience is also important. You lost a lot of weight and then gained some. That can be perfectly normal! A lot of that weight was water weight. Perhaps you gained back some water? How many weeks has the regain been going on? 1-2? 5-6?
I think someitmes our biggest enemy is ourselves in this process. For instance, I lost a pound last week and gained back 2 this week. My eating and exercise were good last week. Why did I gain? Who knows? After all, most of our weight is water... I might not have lost fat last week, but been a little dehydrated... it can make our heads spin!
So, you have to sort of set your mind to be in this for the long haul and find ways to keep committing to the process, even if it doesn't show immediate results!