Hi David, welcome to the forum🙂 Alcohol isn't prohibited, nothing is really, but you do have to learn how it affects you. I find that I can drink a reasonable amount and it doesn't affect me too badly, but others are different in their experience. What I have found is that I'm much more conscious of my diet - types of food and drink - since diagnosis, and I think this gives you an extra incentive to look after yourself better. So keep the drinks for special occasions and you will be able to enjoy them much more without adversely affecting your health long term.
If you are recently diagnosed, then it is likely that you have ben running higher than normal blood sugar levels for a while, and this can cause mood swings - they should improve as you learn to gain better control and bring your levels closer to 'normal'. Depression may also be due to the shock of diagnosis, and hopefully as you learn more this will ease and you will become more confident and not let diabetes rule your life.
Feel free to ask anything you are unsure of, or rant and moan, whatever, and we will do our best to support you🙂
