Feliway Diffuser
I purchased these feliways before, as we had great results with our previous cats. So now we have a younger cat & wanted her to feel safe & secure, as with her being young & flighty, we thought this would calm her down a bit & we think it has, as we've seen a more contented little cat & she seems much more relaxed. I would definitely recommend you try them...& I know that they are a little bit expensive, but once you have a plug-in, the refills are ok.
I would recommend using them for either month on/month off, or 2 months on/1 month off, as the pets get used to them, so having the break will help.