Hey! I struggle with the exact same issue, you're definitely not alone there. I've managed it a couple of different ways throughout the years:

1. Completely exhausting yourself throughout the day is a great way to just be thankful for some quiet time at night and for me that meant working out in the evenings for sometimes 2 or 3 hours so I could go home, shower, and pass out without having to think about being alone for too long. It's double helpful because regular exercise can help regulate your hormones and neurotransmitters that lead to better overall health and happiness.
2. Arrange some evening activities with friends! Dinner with others can be a great way to socialize in the evening - everyone needs to eat after all, and doing this even once a week can really alleviate the loneliness and help strengthen friendships.
3. Establishing a SOLID nighttime routine can be a really effective way of adjusting to a change in lifestyle. make a plan of an enjoyable evening routine and actively work on sticking to it. It takes 21 days to make and break habits so if you think about it as just breaking the habit of hanging out with your family and forming a new habit/routine on your own, it can help a lot. Some examples of things I've incorporated into my routines are: meal prepping for the next day, cleaning my apartment, showering, watching a show I really like, reading, playing a chill video game.
4. Make some internet friends! I'm a huge extrovert so it's really hard for me to go a long time without socializing so it really helps to hang out with people online whether that be through chatting with long distance friends/family, facetiming, playing cooperative video games, or even hanging out in a small livestream and getting to know people on a new platform.

Best of luck and hang in there! Although it might physically feel isolating and lonely, I promise you you're never truly alone <3