I have had some experience with liver function tests. I drank heavily from my teens until last January when I was 38. I obviously took around 18 months off booze x 2 for two pregnancies and breastfeeding but otherwise, I would get through 1-2 bottles of wine a night on Friday and Saturdays, although I didn't drink during the week. I have liver function tests every 2 years with my work medical and had no problems at all until last Jan when they were slightly raised. I had had a big session the weekend before the tests so i was certain this caused it, but my GP then re-tested me every 2-3 weeks. It took two months of complete abstinence to get my results back to normal.
Having those slightly raised LFT's was one of the best things that has ever happened to me. I knew I was drinking too much but the thought of a dry birthday, holiday, Christmas, BBQ, hen night (any opportunity to drink really), was terrifying, however staring down the barrel of possible liver damage was much more frightening, especially given my dad died from liver cancer caused from drinking. So now, although my GP says I could revert to 1-2 glasses of wine on a Friday and Saturday night, I am actually too frightened to drink on anything but the most special of occasions. I never drink at home anymore and have been on several nights out where I haven't drunk, including a hen night. I find Becks Blue is great when you want to feel like you are drinking and 'part of the gang' if that makes sense.
On the odd occasion I do drink now, I can manage to have one glass and then stop, because my tolerance has re-set itself and whereas I used to be just warming up after a bottle, I actually feel drunk after just 1 glass now.
In answer to your question about being able to enjoy yourself, I didn't drink last Christmas because I was getting liver pains which the GP though were probably gall stones as I wasn't honest about how much I was drinking. He got me a liver scan for 28th Dec to look for gall stones, but being so worried about what they would find I didn't touch a drop all Christmas. It was the best Christmas ever. I wasn't annoyed with my two young children when they bounced in at 5am Christmas morning because i wasn't tired and hungover. I was as excited as they were, watching their delight at their stockings, whilst DH missed it, sleeping off his hangover. I remember their faces opening their presents because I didn't spend the day in a champagne induced fog. I wasn't too busy drinking sherry to put their new toys together and sat watching the Christmas film with them with a big box of chocolates instead of falling asleep on the sofa. Then Boxing Day I got to do it all over again, bright as a button because I went to bed sober, at a reasonable hour Christmas night. I won't be drinking this Christmas either.
Good luck.