If you spoke to your doctor, were honest with him about your alcohol usage levels and he prescribing you medication to help with the withdrawals and you are struggling then you shouldn't second guess your primary care physician.
Words of advice- use them exactly as prescribed, speak to your doc on your next visit about your concerns (maybe make one tomorrow for soon if you don't have a follow up set) and if you feel strange about taking them- go sit in the waiting room and see your doc immediately (like the next morning).
We have doctors for a reason, again I predicate the above on your honesty with him/her when you spoke about your situation and their knowledge of you as their patient.
If you just doctor shopped or saw somebody you've never seen before, I'd probably think twice about using meds without a second opinion.