Well drinks and other thing "help" a little when you're already into it. Otherwise there is not really much use of it unless you go completely "sh*tfaced"

I'd take it easier and would start exploring myself before engaging into anal sex. You have to learn your anatomy and discover what you like in this respect and how you get there. The pain is a sign that you have defenetely rushed into it and did not prepare a lot. For the start I'd recommend to get clean and very aroused, an orgasm would be defenetely a good thing. Then start with a dildo like the ones below or similar, it depends on the materials you like:

Blush UR3 Anal Starter

or a silicone alternative:
Sedeux Please

To grow up I'd suggest:
Pure Skin Player jr

The silicone alternative is:
VIP Super Soft

Don't rush get comfortable and try different positions, angles, sizes, etc... After a few sessions you should be quite comfortable with anal penetration.

A good thing to prepare for anal sex is a butt plug, there is a variety of them on the market and gain you will figure out through trial and error what you like best. I recommend using them after you get clean and wear for up to 30 minutes before you start with penetration. However some of them can be used for penetrative stretching too. Below are the ones I personally love and have reviewed:

The best training of all times (after you grow out of the beginners toys):
Triple Ripple

Best Butt Plug (I guess many will agree):
Ryder

And finally my personal favorite among plugs:
Gapers Organic

After a while you might get up to a level where you feel total comfort with only a little warmup before. Be sure to use a lot of lube and again try and find out which one you like the best. Have fun!!!

start with a beginners toy to start before you have your partner join in.