I've really made an effort to embrace what it is to be independent in a committed relationship.
100% a major key to healthy relationships right there. Doesn't guarantee one will work out, but they're much better positioned if both people were happy alone and had their shit together and weren't lacking anything other than a partner. Makes it a lot easier to ride out the ups and downs of life and relationships vs. people who end up co-dependent and/or bring a ton of individual baggage and issues they haven't properly dealt with into the relationship from the start.
End of the day, another person can add to our happiness, but they aren't responsible for it. Having that mindset both makes relationships less likely to end up co-dependent, makes it easier to take fair stock of relationships and not cling to ones that aren't working and aren't going to, and makes break ups a bit easier to get over as your happiness, worth etc. isn't totally wrapped up in one person.
I'm going to be honest, and it may come across as a bit harsh, but this is not the first time your GF has mulled leaving you, and for whatever reason she did decide to give herself space, that was likely the breaking point for her and not some radical change in behavior.
You truly and honestly need to be introspective and ask yourself if what you want out of this relationship is still the same thing she wants. Because my read of this situation is that she is, and likely has been, unhappy for a time much longer than her supposed behavioral change.
For sure. Space is needed and some hard talks. Though if she hadn't communicated whatever doubts, concerns she's had over time--if she has indeed had them and they led up to this--that's on her and not a good sign of emotional maturity. Of course, we only have one side of the story there and she may have attempted to communicate things and just wasn't heard, or wanted changes not delivered upon etc. which is a different story.
That said, it also could be a newer thing. He states she had little to no interest in sex over their time together until recently and finally getting off birth control and her libdo going through the roof. That's major change from having pretty much no interest in sex through her 20s to mid 30s to having a ton of interest in sex. So that could cause a lot of thinking about what she wants going forward as it's a whole side of her self she's never explored that's recently emerged.
This is an entirely different situation but if there was one thing I regret from getting out of a long relationship and being left was after I was starting to get over her after about a year to let her come back into my life and miss me and then having her rebreak my heart again and lead me on. The reasons for breakup didn't change so I should have known but I was letting my heart lead. Although it taught me a lot and helped me for the future…
Yeah, had a similar experience with my first long term relationship. While there's exceptions to everything, if a partner breaks up with you or vice versa it's usually best to just make that permanent unless there was a very clear reason for the break up that was fixable and got fixed, anyway.
Doesn't apply here as his GF hasn't broken up yet and asked for time and space. OP should give her that for as long as he's willing to wait (with in reason of course). If she ends things, or he decides he isn't willing to wait any longer, time to move on for good IMO.