I would say not to force yourself to go to an event that would make you feel uncomfortable and maybe even a little bad by its conclusion.
Your lack of interest may be a combination of things. Who knows? The point is that you don't really feel like going so, follow your gut and don't go. Another event will come along soon enough.
I understand the need to get yourself out there and put some effort into making a few changes now that life has tipped upside down. As my dad used to say, the pen doesn't write unless you move it. BUT, there are so many other ways to get yourself out there. You certainly don't need to just be the mom all the time. At the same time, there are hobbies, sports, girlfriends, PTA at the kids' schools, volunteer opportunities, cooking classes, photography classes, travel groups, etc. etc. All those things are out there for you to explore.
I'm the same as you - I'm just really apathetic a lot of the time about dating. I haven't done it yet and don't know when I will. It's not like when we were younger and there wasn't much effort that went into it. Now, there are kids and jobs and homes to take care of. I have no idea how people even find the time.
Sometimes, it upsets me and makes me feel like I'll be alone forever. My IC always tells me that finding my way in this new life and perhaps finding a new partner doesn't necessarily start with online dating. She said the only thing you need to do is expand your circle a bit. She actually told me that she doesn't give a shit if I want to join a knitting class with a bunch of 80 year old women. Those women are new people who can then introduce you to more new people and then, before you know it, there are new friends and new people coming into your life with all sorts of possibilities that you never imagined during your M and the D process.
Don't put so much pressure on yourself. There are so many more ways to find a new beginning.