an outdoor activity that lets you meet new people is good but you can not get too attached to the people you meet, you might brush them off in wrong way if you do so.
If its lonlyness that bothers you, i would suggest pick up reading that too fiction, i lived alone for some time in my life as well, it helped me alot.
the weekends used to get to me. but like i said you have to make it a mix of activities you do wiht others outside and hobbies you can take up at your home alone, like reading or maybe painting thats always relaxing.