Cara
Like you, I have hunted high and low for fresh yeast, but to no avail. For my bread, which I made by hand, I use Allinsons Dry Active Yeast which Olivers sells (but it sells very fast!). I activate it first as I find the results are better.
But if you use a bread machine, fresh and active yeast isn't suitable, i.e. you need to use a yeast suitable for these devices, one which does not require pre-activation with hot water. Look for Fast action or Easy bake yeast. Check the box - those suitable for bread machines will say so on the label.
BTW, if you're not too concerned about additives, you can also add bread improver. Ask at Great bakery section.