It's so hard to meet people I find too. Other mum's in the playground really do seem to find single mum's a threat and even the two good friends I have rarely invite me around because I'm an odd number at their dinner parties and can't afford to reciprocate and have to bring my child with me too...
And the two other recently single mum's at school are happy to chat in teh playground, and one is always saying 'oh i'll go out with you', but is only now just realising taht being single pretty much equals having no money for a social life!
The only solution is really to find ways of filling your time and to find activities you can join which people go too as a single person (even if they are not single)
I do try and keep my days full now, but I still wonder how I'm ever going to meet someone if I can't afford to go out socially and I live in the back of beyond which narrows down the options on meeting someone anyway.
However, I have joined a local lone parent group which has been really good for finding people in my same situation and to have someone to go along to things with and just to have a little adult company once a month and know there are people on the end of the phone I can call now.
What about a hobby or activity you can do at home to fill in your time? Cross stitch, crafting or something like that? Then you might find a local group you can join. Or what about the WI? You might find you're welcomed at your local group as a younger member, plus actually not everyone there is over 80. And it's guaranteed everyone there has come alone so no being the only one not in a couple to worry about! ;)
There's always times when you're going to feel alone though and thus lonely. Accept it as part of your life as a single parent, have you moment of self pity, and then move on to filling your time with more practical stuff. Easier said than done i know.
And if anyone can offer you some practical tips on finding and making real friendships I'll be all ears myself as I find it almost impossible no matter how hard i try.