Spider mites on rosemary?

Hi everyone,

Novice/stupid gardener here, so probably made the mistake last year.

I planted a rosemary cutting out into my small garden, it took and grew well. However, it seems to have developed a white/yellow blotchiness to almost all the leaves over winter. My research on the internet suggests that this is due to spider mites. 

Have a few questions:

1) does this sound logical?

2) there doesn't seem to be any decent/cheap way to get rid of them - any ideas?

3) is it the end for my rosemary bush - I'm assuming that it wouldn't be good to use any of those leaves in cooking.

Thanks in advance.

Ian.