I just graduated high school about a month ago and since then I have started to feel really down. I have a few good friends but I don't feel as if I can talk to any of them. I feel lonely and I really just want a guy to keep my company (I have never had a relationship before, just flings). I feel like men just aren't interested in me. I get really down particularly late at night when I am alone and start to think about life. I get this pain in my chest when I think about everything and I don't want to do anything except lie in my bed. I don't really know what's wrong with me, I want to tell my mum or a friend but I'm afraid they will not take me seriously. I always seem to be all right again in the morning and I'm sick of the sudden mood change from happiness to extreme sadness. Please help, I don't know where to go from here.

Sounds like signs of depression. You may want to consider speaking to your mother about this... Then speaking to your family doctor as well.

You are very young and shouldn't be having feelings/thoughts like this. It could also be a huge transition for you. Graduating high school and leaving people behind. When one door closes, another one opens... college...

Try telling your mother.

It has been a while since you wrote this. I hope you are feeling better. Change is always difficult. For me, I find goals help. Even very small goals like going for a walk or reading a self help book. Don't give up.

I went through he same thing at your age, and all I can say is; it will get better.
Get some self help books about depression, these will guide you through stuff, really try not to dwell on things too much- this took me a long time to do, but basically you have to pick yourself up often when your feeling down- so change what your thinking about, focus on your education, but yes you should go to a family doctor and get on a waiting list for a therapist- a good therapist will help you though this, and equip you with the tools everybody needs in life to get through it.
And by the way, if you think men aren't interested in you, you are probably wrong, but a huge amount of boys your age are so immature they just won't approach you! Know this; everyone your age is scared less, and most people are not having that much fun either, even if you think they are.
We are all pretty much the same.

These are normal feelings and justified for we are
All alone in the end and are simply compilations of
A variety of universal elements and nothing more.
However, ignorance can be bliss, so ignore these
Feelings and these facts and live your life the way
You want.

I've went through that as well. It sounds like anxiety and perhaps depression. There doesn't seem to be much information about how you spent your time and other things so I will ask a few questions.

Do you see your friends often? And when you do, do you enjoy yourself or do you feel a little ignored or bored? Do you have deep and honest conversations with them?

What do you do during your spare time? What are your hobbies? Do you go out often (even if it's just a walk)? Do you learn new things? Meet new people?

And are you introverted? Introversion is the inward focus of the mind, where you find your "batteries" drained when you have been with others for a long time and need to be alone to "recharge". Or, as Wikipedia puts it: "Introversion is "the state of or tendency toward being wholly or predominantly concerned with and interested in one's own mental life".[4] Some popular writers have characterized introverts as people whose energy tends to expand through reflection and dwindle during interaction."

I find that, sometimes, introverts might tend to focus so much on their thoughts, feelings, and focus so much within themselves that they are sensitive to every fluctuation of their emotions and thoughts and this large amount of focus leads to anxiety. It is healthier to balance this with focusing equally with the external world. An extrovert may be more likely to focus more on the external rather than the internal than introverts who do this (ie. Planning out their activities, etc).

So I think it's good to take action to alleviate your loneliness rather than wallowing in it. Take a walk, join a photography class or some other class that you may be interested in, join a sports team, take up music lessons, sign up for a race, visit the art gallery, go to the library more often alone, etc. While doing this, be open to the possibility of meeting people wherever you go. Take the liberty of striking up a conversation with the cashier or bus driver. Don't feel badly if it goes awkwardly the first few times, but eventually, increasing positive interactions may alleviate some loneliness even if it is a deeper connection that you are seeking.

I've met people at the store, on the bus, and at the library. It all happened suddenly and I have to admit that I was scared but they were mostly positive experiences and increased my likelihood of meeting others, including men, as some of these interactions were with males who seemed interested. What I am trying to communicate is that you should put yourself out there more, not for the sole purpose of meeting someone but to enjoy yourself and to experience life, even if it's just a walk through the park. It could also help you create social relationships or even just momentary social interactions that can help you in so many ways - in lifting your spirit, in helping you put yourself outside of your comfort zone, by taking your focus away on how you feel, by bringing your inward focus outward, by helping you build your social skills by interacting with complete strangers (if you don't already), and by increasing the likelihood of meeting someone.

It's an ongoing struggle, to keep away from giving in to anxiety, melancholy, and depression but you can do it. It involves patience, love, and perhaps a shift in perspective and focus. I wish you all the best.

All of your problem is just need find someone to communicate.
You need listen some music, do some sport, and just get out of your house to meet someone.
Believe yourself, absolutely, you can find your real friend one day.
Meet more people at college, and keep any relationship, this is my advise.