First of all, 30’s truly is the new 20’s. Hence, do not feel sad that your 20’s are getting over.
Having said that, it is definitely a milestone you are going to attain. Hence, it deserves special attention.
As your life experiences may have taught you, especially in the last few years of becoming a more independent person, that life is best when we take charge of it and take responsibility for our own happiness. On that note, how about you decide to make the next 6 months memorable in your own special way? You can pamper yourself by doing things you love, things you always wanted to do but never dared to, and do some soul-searching on what you have learnt in past decade, what makes you happy and how can you go closer to your life goal in the next decade.
Make it a point to do one pampering thing a week (get a manicure / listen to favourite music while going to bed, etc), start taking greater care of yourself (fitness, skin care, nutrition, mental peace), look around you to have nurturing relationships and make an effort to be there person you want to be.
At this juncture, you would notice you have evolved in the past decade and some of the things you used to like and people you used to hang out with, are becoming difficult to connect to. Try to politely move on, and make an effort to socialize with people who suit your interests and lifestyle.
Most of all, spend five minutes every day to thank God for giving you an opportunity, a luxury to celebrate last six months of 20’s. In a world full of catastrophs, health disorders, lack of access to bare minimum living standards, you are blessed to be alive.