first of all there is no point repeatedly shrinking the log if it just having to grow again - and shrinking a log does not remove data from it.

From what you describe the first thing I would do here is back the log up more frequently.

If your disk can handle the size the log is growing to with 2 hourly backups don't worry about it. Set the log to the size it needs to be to handle your activity, set a sensible growth factor and leave it there.