Once in a while I start to get this weird feeling. Like sort of being sad but I don't really know how to explain. Usually it goes away quickly, like only lasts a few days but then I get distracted and move on. But this time it is lasting much longer. It has been over a month now. I haven't been wanted to hang out with friends and I've been feeling weird about my boyfriend. That's the part that scares me the most because I love him and don't want to lose him. (been together for almost two years). I just feel so detached from everyone. I am going to college next year for dental hygiene which has a lot of homework which I have been thinking a lot of lately. I want to think that I am just stressed but I'm not sure. I just want to be fixed and go back to normal but I can't because I don't even know what's wrong with me. I'm even crying while writing this because I just feel so sad about it. I feel sad like 90% of the time. The only time I'm like 100% distracted from it is when I'm hanging out with my sister. Anyway I'm just looking to see if someone has gone through the same thing, or someone who might have an idea as to what my issue is..

Yes, of course, many of us - it's depression. Depression is when you can't put your finger on what's getting you down, and when all the negative emotions mix together in a dull way, or not so dull, because you are crying now. That's a GOOD sign (relatively) that what's really going on is close to the surface, and with a little help you'll be able to identify the grief, hurt, anger, or guilt, or combination of any of those. For many young people who haven't been through a death of family, abuse, or other trauma, it's almost always hurt and anger. You can throw in mistrust, betrayal, unfairness, whatever you want, but everything goes back to hurt and anger.
If you think it's more vague and long term than the last month or so, it could be part of that dreaded confusion of the teenage years, when we are supposed to know what we want to do as adults, but don't. We might see parents who are happy doing something else (housewife and mother, perhaps) or we might have unhappy parents, and we don't have any role models, corny as that sounds.

If either of those tracks sounds right, can you talk about it here? Or see a therapist for 2 or 3 visits?

[I see that I and others suggested therapy in January. It would be better if you would add to older posts you started. Anxiety and depression often go together.]

Everyone I know goes through this feeling several times in their life,including myself.You seem to be worrying about things that may or may not happen, also how much work is involved when going to college, I wonder if you have made the right decision for your future maybe you need to talk that through with someone who is doing this studying just to set your mind at ease.You say you only feel 100% with your sister I think this is because you know she will always be there for you but you seem to have doubts with everybody and everything else.

Maybe you are lacking in something( vitamin wise) if you have been down for a while with no obvious reason perhaps a visit to your GP may be a good idea just to check all is well with your health.

It's depression. I suffer from it frequently, to the point where I take medication for it, which helps a great deal.

Depression happens to everyone. Sometimes it's only for a day, with no reason at all that you can think of. Sometimes it lasts weeks, or months, or even years. It's a chemical imbalance in the brain.

Depression happens when people die, or you break up with someone, or something bad happens. It can also happen for no reason simply because the chemical balance in your brain, is off.

Talk to your doctor about this. No shame in taking anti-depressants. They do help. If you need them, look into it, find the one that works for you, and it will help a great deal. It did for me.

I'm on Celexa, have been since the year 2000. I've had no adverse side effects, was able to take it while pregnant with my daughter and there were no side effects for her either, she's now 13.

Talk to your doctor about this. It's not as uncommon as you think. So many people are on anti-depressants now. They don't talk about it, but it's very common.