Hi.
Got your PM and really no problem at all.
I read through this thread and here's my thoughts.
1. Are you happy with the way you look right now? Personally I can't imagine weighing 140 standing nearly 6' tall, but my preferences are not yours so I don't know. Is the really skinny-guy-look the one you're going for?
2. You dieted using far too low a caloric intake which certainly led to muscle loss.
3. You admittedly didn't exercise much which further solidified muscle loss.
4. Losing weight is easy. Losing weight and getting lean is hard, relatively, and when you don't do it right, more often than not, you end up a lighter, still soft version of your former self.
Harsh reality.
Where do you go from here?
Well if I were in your shoes I'd be damned if I lost more weight. You already are skin and bones if you ask me (please don't take that the wrong way). Losing more from where you are now would probably make you look sickly. Would it expose your abs? Eventually most likely but you'd look like you're a walking skeleton right out of a concentration camp.
Even then there's a chance you won't see your abs.
See the attached photo. That's from a often referenced study known as the Minnesota Starvation Experiment where men where starved in a controlled setting to mimc nazi camps. They were not fed adequate calories, adequate protein and they certainly didn't lift weights.
Is that the result you're after?
Personally I would scratch the abs and bulk back up to a respectable weight and do things right. It's winter time now anyhow (depending on where you live of course) which is the best time to bulk.
Once you reset some things, start fresh with more muscle mass and focus on losing fat while maintaining muscle.
That will be your best bet of looking lean and healthy.
Even then you might not see your abs nicely. It's very genetic too. But I wouldn't bank on that until you actually give it a try using proper principles.
Probably not what you wanted to hear but you asked for my opinion and now you have it, lol.