It is none of your friend's business what medications you are taking for pain. I learned this the hard way and most of my friends assume I am a pill mill addict because of what they have read and seen on the news recently about oxycodone.
As long as they see that you are able to do more things with them, they should be grateful that their friend is able to engage more with them in life.
There are many chronic pain patients that need to take some sort of sleep aid to counter the alertness brought on by some medications. There are tranquilizers or hypnotics that you can talk with your doctor about that can help you get a better night's sleep.
The big question is, Is the Savela helping your pain from Fibromyalgia? If so, then also ask, Have a tried the gauntlet of other meds out there to see if they help with my pain as well without the side effect of insomnia? If the answer to the last question is no, consider talking with your doctor about other medications that you could try that might be as effective but restore some of your sleep back. If you have already tried a slew of medications and the Savela is the diamond in the rough, then consider having a discussion with your doctor about a medication you can take before bedtime to counter the effects of the Savella so that you can get some sleep.
Sleep deprivation often makes chronic pain worse. It is important to get a good night's sleep so that you body can recharge and heal itself so that it will function better the next day. And again, your friends don't need to know the details about what meds you are taking for your condition. All they need to know is that your condition is being treated and that you feel better from the treatment that is being received from your medical team.