This is what I've done...my weight fluctuates SO much I'd be constantly in a lose or gain mode if I didn't have a range. If I drop below 138 (which was my lowest weight, when I started really maintaining) I'll look to gain a bit, or get above 145 I'll look to lose...

I have been afraid to gain, even when I knew I was a little low and needed to gain, yes. Early at the first of the year I drifted down to 115 for a brief period of time. I really looked 'too skinny', so I knew I needed to gain a little back. Got back up to 120, but found myself pulled by the fear of weight gain so cut my calories back down drastically, back down to 116. At that time I decided I needed to weight range with a top and a bottom, and I needed to pay as much attention to the bottom as the top. I had to revisit my redlines after some surgery, but I still have that fear of gaining. I have been comfortably in the middle to the top end of my range for a while, so haven't had to deal with that, but I can tell you it was a little scary when I got too low. I could feel myself thinking several different things - "cut another 200 calories per day and I could lose a little more" running in my head in tandem with "have to up calories and gain back, too skinny" with the "no more calories or I'll gain it all back" as the more continuous one. I do remember being physically scared to eat for a little while, because I was convinced I wouldn't be able to control it. It has gotten a lot better now that I've been in the higher end of my range.

I've read some of your other posts about continuing to lose, it sounds like you just haven't found your maintenance range yet. Also scary, the thought of adding the calories back in immediately put me into the scared of potential gain place - I added the calories back in slowly until I felt settled and stopped losing, 50 calories per day the first week I think, another fifty after week 2, etc.

Good luck.

I totally relate with you. I am at a point where people are telling me I lost too much and I agree with them whenever I look at the mirror.
I want to put 5 more pounds on, but I am so afraid it won't stop there.
My plan is going for a vacation the next month and stop worrying about the weight at least for those 2 weeks and when I come back try to stay at 5 more pounds than what I weight now.
As the holidays are here I am actually in peace with those extra pounds because I am planning in getting some back anyway...
But that is exactly where your concern comes in place: I am terrified it won't stop there... but it is about will power and mindset. I have gone to vacation before gained some weight and was able to go back to the "lose weight mode", so that keep me optimistic.
Can't say if my plan will work... but I'll give it a try.
Well, my point here really is to show that you are not alone.
That fear is understandable, since once we didn’t have control over food and we are scared it can happen again...

Maintenance Weight Range