Hi Maddawg, nice to meet ya,
Your first problem is that you are not willing to talk to anyone close about how your feeling, if your family life is void of bad things i would say its perfect, so go talk to mom and dad, they have been here much longer and will have ideas of how to improve things, you may not agree with them, but you will have other angles to look at.
You say that you do not feel you excell at anything and are kinda middle of the road, well i disagree, firstly you have the ability to convey what you feel in your message, this has been done very well, and easy to understand. secondly, you are obviously a person who can achieve, you say that you are 'pretty normal' in order to be able to say this you must have achieved the ability to grade yourself amongst others and give a comparison, unbelievably, a large percentage of people do not posees this ability and feel that they are either 'gods gift' or 'a dog', as to being an after thought, now thats simply a fact that in many cases peoples lives are running at different paces and in different directions, it doesnt make you any less important, or an afterthought, just that whatever they are doing may be , in their mind, more suited to the present company and not with others. Would you invite yor friends to every activity that you do in order to stop them feeling left out?
Dont feel weak, or pathetic, for being human. you have as much strength, and as much worth as anyone you know or will know in the future, i have a feeling that you are going to find life much more positive very soon, and as many do, you will find where you excell, an example of this is my friend, he was never really the 'popular' one, and seemed to be lower than average in learning, when he reached 23 (a few years ago now) he decided that life wasnt what he wanted it to be and set about rebuilding it. in 2 years he had built his own electronics business, had amassed a large group of people who classed him to be a friend and worth knowing, gained a wife and soon after a baby boy. If he can do it than anyone can.
Talk to your parents, they wont think you are weak, they are more likely to realise that you are becoming a stronger person. To talk to others without fear of ridicule gains more respect than you could imagine, it is more likely that they are noticing how you are feeling and not mentioning it because they dont think you can take the advice, especially if you are intentionaly avoiding doing it.
You have mad ethe first step by talking on here about it, thats stronger than you think, there could be as many as 10,000 you have now spoken to, not just the 2 at home. Go talk and let the ones who really know you help you to put this all behind you, then you can progress to be the person you want to be.
i wish you the best in your future and all you do.