At diagnosis I vowed I would ever let diabetes inhibit my social life, as that would impact on others too. To be clear, I'm not suggesting for a moment I'm the hub of any social gathering, but if I choose not to attend something, it's unlikely my OH would go without me.
If we're going to friends, then I'm likely to know the sorts of things we're likely to be fed, so can plan accordingly, but if I'm "going in blind", I'll ensure that I'm not going to be starving hungry when I get there. I might just have a portion of yoghurt, some cheese or pork scratchings before I go, then if my comfortable choices are limited, I won't be gnawing on a table leg or fainting in a corner. At events or functions, I make the best choices I can, and will sometimes have a very small portion of something I have no intention of eating on my plate, so as not to draw attention to a plate with (to some) bizarre food choices on it. Thus far it has worked for me.
To be honest, diabetes is rarely a huge challenge. I find staying gluten free much more of a challenge, as it can be hiding in the most unexpected places.
On an aside, I'll usually have a small pack of nuts in my handbag when we go out - as "emergency rations". It's a long, long time since I had to break into them, and last time that happened it was due to a logistical hiccough when travelling and an expected lunch just not happening.