Yes you are best off not trading one addiction for another. Benzo withdrawals are FAR worse than opioid withdrawals.
That said, using benzos will help tremendously with sleep and anxiety.
Gabapentin or pregabalin are also wonderful medications that help tremendously with opioid withdrawal. They can be habit forming as well but like with a benzo if you only use them short term to get through withdrawals this isn't an issue. These medications help even more than a benzo in my opinion as they tend to help mask the symptoms of opioid withdrawal better.
Using stimulants during opioid withdrawal is a complicated thing. Some people find they make them feel much worse, others say it helps. Who knows how it'll effect you. Same rules apply if you decide to use the focalin: becareful not to trade one addiction for another. You are much more susceptible to a new addiction during this time.