Not alone but lonely

I feel a little stupid for how I've been feeling lately. I have the bestest friends I've ever had who genuinely care about me and want to spend time with me, but for some reason I can't get over that lonely feeling. My two closest friends are dating each other so I have to watch them cuddle and stuff while I third wheel even though they always make sure to include me in things when I'm there. The person who used to be my closest friend got realky distant randomly and won't hang out alone with me anymore. So I can hang out in groups but I can never get any one on one time with anyone. Is that me being selfish? I just want a close connection with someone and I'm told I'll find that in a significant other but I can't find anyone I like that way. Not too sure what I'm supposed to do about this.