<human>: Can you summarize the given text in a few sentences?

21F, am single and in college.  Have been dating casually for the last few months - am seeing someone now.  Have plenty of really good friends, people that I can call up if I ever need anything or want to talk.  But sometimes I feel like they're too busy for me, which happens sometimes.

I notice that I have a really hard time being alone.  I feel like I always want to be around other people - friends, romantic interests.. anybody.  I don't know why I feel so uncomfortable just being alone, especially at night.  I struggled a lot with this when I was a freshman/sophomore in college, but now it's sort of resurfacing now that I'm a senior.

Why do I feel this way?  I just can't stand spending time alone... I just feel so helpless, bored, and generally not good about myself.  But when I'm with other people -  I'm energetic, friendly, talkative.  When I'm alone, I'm low energy and unhappy.  I know that I have friends - I never feel like I don't have friends, or that I'm not an attractive person or a person worthy of talking to/hanging out with.  But when I'm alone, I always feel so terrible, and I text all of my friends at once so I don't feel even worse.  Maybe this is normal, but it doesn't feel like it.  Maybe I need more external validation than I think.  What can I do about this?  What do you guys do when you feel lonely?
<bot>: I like myself, I have friends, but I feel very lonely whenever I'm not around other people.  Why is this, and what can I do so that I am more comfortable being alone?