Jaylou, you sound just find to me. Bloody in-laws, who needs them? 
(Well, we do for babysitting 
.)
Agree with all the previous posts. I hate forced group situations - like M&T groups - where you're expected to gel with a load of loud women you'd have nothing to do with if you didn't have a kid.
And everyone's different: some people like big, loud social situations, and others - like me, and probably you - thrive on mixing in small groups of people, or one-to-one. That's just personality differences, and it's absolutely OK; part of life's rich pattern, and what stops us all from being boringly similar.
My ds in now almost two. In our old house, we used to go to the village M&T group sometimes, but I never really felt at ease with it. Now we've moved, we've got locals pressuring us to go to the one in this village? Why?! It's just not our thing.
There are about four/five other mums with little ones who we see regularly, and who've become friends. We see them just one at a time, at each other's houses; the kids play, we chat, and it's easy and comfortable. And all grandparents are local, so we see them a lot too. This all works out great. Definitely agree with previous poster that little ones need love and security way more than socialising with peers, up until the age of about three. And toddlers don't even play together until they're two or three anyway.
M&T groups and coffee mornings are overrated in my opinion - they really are great for a lot of mums, but they're not compulsory or a necessity.
I think you're doing just fine.