I just think these things take time, you can't rush it.
Carry on with your planting, although it doesn't neccessarily need to cost a fortune. Grow stuff form seed now for next year if you can. You get loads of plants and probably of much better quality.
If you provide the right plants/ environment- wildlife will come of their own accord, it just wont happen overnight or when you want it
I put in a wildlife pond last year, I now have a toad and tadpoles.
I don't think the weather has been great either but don't give up, just keep going