I have a suspicion, based only on my own experiences, that once cypro has done a number on your T level, the deed is done..
As Kay mentioned, depression is (can be) a side effect of cypro, one I have experienced. Dose changes and even not taking it for some time did nothing to increase my T level - it did, however, relieve the depression. My libido never went away, sure, it changed, but it's still there.