Both naltrexone and gabapentin can have serious emotional side effects especially when combined with alcohol. You don't mention which antidepressants you're on, but alcohol is not recommended with those, either.
My point is that these feelings may well be created or made worse by the medications you're taking...and they definitely would be made worse with drinking.
Is your doctor aware of your drinking history? It may well be time to have a review of your medications with him/her and evaluate their benefit versus these side effects.
We tend to assume that we are sad and miserable at our core when in fact these emotions are often caused by what we're putting in our bodies, especially as some if us are super-sensitive to medications and alcohol.. I know I am far more emotionally stable sober than I ever was drinking.
Schedule an appointment, yes?
Sending you a hug.