Thanks for your query.Based on the facts that you have posted it appears that you have facing problem of Erectile Dysfunction
since very recently particularly when you started consuming alcohol.
I would like to state that consuming alcohol is one of the most important causes of erectile dysfunction.
Since you were getting good hard erection your present problem is termed as secondary Erectile dysfunction and could be due to alcohol consumption and partly mind related
Following measure will help you to boost up your confidence and getting good erection.
1) Practice regular exercise for 45 minutes followed by meditation
for 1/2 an hour in the morning.
2) Take high protein diet rich in vegetables and fruits and Vitamin A
3)Take anti oxidants like Almonds 5-6 everyday..
4) Avoid alcohol and smoking