Has anyone experienced this (male's perspective)

[Overthinker1234]

Hi all,
I’m not usually one to post. I tend to solve things privately or through reading. But I’ve hit something I can’t work through alone.
I’m 32, male, and pretty self-aware when it comes to psychology and relationships. I’ve been with my fiancée for 3 years. She’s amazing, a brilliant mum, hardworking, kind, and trustworthy. We live together, and both have children from previous relationships who get along well.
Every year, she takes a 3 to 5 week holiday abroad with her young son (who I adore). She absolutely deserves the break. But each time she goes, I’m hit with growing anxiety and insecurity and I can’t explain it. She’s done nothing to cause concern. I trust her. And yet, I spiral.
I wonder if it’s about other men sexualising her while she’s away, or just my own fear of losing her. Either way, it feels irrational and out of character for me.
I’d never want to project this onto her or make her feel guilty. If I can’t get a handle on this, I’d rather walk away than damage what we have. But I love her and want to be with her. So why does part of me feel like running?
Has anyone experienced anything like this?

The anxiety has no basis in your day to day reality so I wonder if this is something from childhood. Maybe investigate therapy to work it out. I find talking to my child self and soothing myself really helps with my fear of abandonment.

Why does she go away for such an extended period each year? That may shed some light on the situation.

As someone whose partner worked away a lot, I can relate to your having issues with it, but not the feelings of insecurity/jealousy in the relationship itself. (It did ultimately drive a wedge as there was no consistency and I found it too disruptive. It included a lot of school holidays, which I found very hard).

Is the 5 weeks all in one block, or spread throughout the year? Does she give your relationship equal attention? I'd wager your feelings are stemming from not having your needs met in some way, and as much as you try to rationalise it, deep down its not what you'd wanted from a relationship and it's manifesting in feelings of jealousy? I second the need for exploring it in therapy, and also in communicating your feelings about it with your fiancé.

Other men are sexualising her every single moment she's in public. In her jogging bottoms, in Sainsbury's, walking down the street.

This! Why would your partner being in a different country for five weeks cause this sudden occurence of other men sexualising her? It happens when she's in the same postcode as you, further, why is other men seeing her as a sexual being so distressing?