It would seem that hoisted up judgeypants have caused a certain shrillness in some of the responses you've received. MrsJAT.
I'd still like to know the backstory of how he came to be off on a jolly while you're stuck working and, in asking, I'm mindful of a recent post where a similar age OP's new manchild dh rapidly became accustomed to an inequal division of labour on the homefront as well as her funding his activities elsewhere.
FWIW, given that he's not on a business trip or taken himself off to a certain clinic not too far from Lake Garda as the crow files, I see nothing disparaging in offhandedly describing his jaunt as a 'jolly' and, with the proviso that you're not too far from his thoughts, I hope that he's having a jolly time on his hols.
I consider it's impolite to bill and coo in any phone call to a significant other that's made in public, but I wouldn't have any compunction about ending any such call with 'love you' rather than 'over and out'. Can't he call you/you call him when he's in his room or on his own so that you can engage in a more intimate dialogue?
Insecurity is no respecter of chronological age and no matter how many rings we may have on our individual trees, so to speak, we can all feel 16 inside.
However, with the benefit of hindsight, I reckon you'd be telling your 16 year old self that there really is no point in allowing the demon of insecurity to torment you as there's nothing you can do to stop a guy cheating and/or walking out on you and, if he proves to be a shit, you'll get over it.