Signs Of It Being Over?

A principle fact on reading people is that you should never go with what people tell to you, it's HOW they tell it to you.

Body language can tell a lot if you're unsure about your partners feelings.
Some general IODs (indicators of disinterest) are: Turning away a lot from you, not facing directly towards you when speaking, yawning when you speak, never initiating conversation with you when you stop talking, not keeping eye contact with you, keeping away from your touch, not initiating touch with you, moving away/leaning back when you come into her "zone", folding arms across his/her chest, not laughing as much as before (laughing is an indicator of interest) etc etc, the list is endless.
Of course, most of these IODs should be taken with a grain of salt as sometimes there are just reasons why people would for an example fold their arms (e.g. that it's cold or something) or maybe yawn, they are by no means a definite answer but I can tell you if you meet too many of these too frequently I can tell you that your partner has most probably already played with the thought of breaking up with you.

Sometimes you can even find yourself doing these, and if that's the case, just end it already.
It's better for both parts to end it quickly and not stay for too long in a deteriorating relationship.

Jam it back in, in the dark.