Feeling bad about myself constantly?

you don't have to get rid of these thoughts; simply replace them with positve ones.
for example, think of a positive thing that makes you happy, god loves you.
can you contact your 2 good friends and maybe you can try to hang out with them?
don't worry, be happy. you are not worthless; it takes time to find meaning in life - group with friends/ enjoy life(watch good movies/ do things that you enjoy doing), and you'd know that life is worth living.
The way to feel good about yourself is to exercise - e.g. go swimming/ jogging.
listen to music may also help. If you replace the negative thoughts with the positive ones, your life might or can become carefree so you can live a happy life.
Same as you, I thought on earth there was no point be to be any longer. but then a friend told me that there's always a way out of darkness. He showed me the way to the light. If you only believe in the positive side of life...you'll see things very differently. please don't give up on yourself. be strong.

Practice a relaxation method, daily, and when needed, such as: (free) http://www.drcoxconsulting.com/managing-stress.html or http://altmedicine.about.com/cs/mindbody/a/Meditation.htm or http://www.wikihow.com/Meditate or Yoga Nidra, (no flexibility required) on page L at your-mental-health.8m.com, below. Qi Gong, Tai Chi, or regular yoga suits others better. They will enable you to emotionally centre yourself, when practiced regularly, and can also help you become a person who is less influenced by the words and behaviour of others. Learn them at least a few hours apart, and preferably on different days, in the morning, or early afternoon. Use the one you find most effective. A minimum of 10 mns is recommended; 15 is better, and 20 is ideally preferred.Learn them at least a few hours apart, and preferably on different days, in the morning, or early afternoon.

Give the EFT a good tryout, to see if it helps you. Use the searchbar at www.mercola.com "EFT" & "EFT therapists", or www.tapping.com (13 free videos) Professional is best. - There is a version for use in public places, (if you want to, you can claim to have a headache, as you massage/lightly tap your temples, but you would then be restricted to subvocalising: saying it to yourself in your mind: "Even though I currently have low self esteem, I deeply and completely accept myself." I have recently encountered the opinion that, just as it is important to build a house on a solid foundation, so it is with self esteem. Learn to forgive yourself for your past mistakes, and failures, or inadequacies. Accept that you, too are just a human being, with the frailties, insecurities, and tendency to err, occasionally, that the rest of us have. That is the beginning of self love, self acceptance, and self esteem. Regularly monitor your internal monologue (self talk): write down the negative ones: "I'm really ugly" and then the converse: "I'm fairly good looking", and next time you become aware that you are thinking the former, visualise, as vividly as possible, a big "STOP!!!" sign, and/or a stern faced person wagging a finger at you, and deliberately repeat 5 times, either aloud, in a big voice, if alone, or subvocally (to yourself, in your mind), the converse affirmation.

Some people go so far as to keep a wide rubber band in their pocket, then put it around their wrist, when they catch themselves backsliding, stretch and release it, as a method of reprogramming their mind sooner, but I don't regard it as being strictly necessary. Volunteer, even from home, at first, to provide a solid basis in reality for the daily affirmations: "I am a good person, who is valued by my community, because I... (insert activity here).." Google: "volunteer from home" More details about volunteering are on page B at 8m.com. Make a list of all your good points, strengths, and achievements. Put it somewhere so you can easily refer to it, from time to time; perhaps on the refrigerator door, or print it; (large typeface, or capitalise) have it framed, and place in your bedroom, or in a position of prominence, such as on the television, or lounge room wall.

See http://www.wikihow.com SELF ESTEEM. Read: The Self-Esteem Guided Journal: A Ten Week Program (New Harbinger Guided Journal) by Matthew McKay and Catharine Sutker, & Healing Your Emotional Self: A Powerful Program to Help You Raise Your Self-Esteem, Quiet Your Inner Critic, and Overcome Your Shame by Beverly Engel & Self-Esteem: A Proven Program of Cognitive Techniques for Assessing, Improving, and Maintaining Your Self-Esteem by Matthew McKay and Patrick Fanning & Happy to Be Me!: A Kid Book about Self-Esteem, by Christine Adams, Robert J. Butch, and R. W. Alley, from your bookstore, or Amazon.com. Hypnosis is merely a heightened state of suggestibility, in which you are better able to communicate with your subconscious mind. 85% of people are suggestible, to some degree, so you could either seek professional hypnotherapy, or more alternatives along such lines may be found at http://your-mental-health.8m.com/blank_25.html about self esteem.

Get a job like babysitting. It helps to be responsible for others.

Maybe you are depressed or just lonely

Meet new friends and start over..but be confident with your self and be your self.

The way you have described your situation seems to me to indicate that you were much happier before you started like worrying about small things the past few months. You indicated that you didn't always feel this bad about yourself but lately you've been feeling incredibly guilty about who you are. Well I'm not a doctor but it seems to me that you shouldn't do that. I'm going to suggest that you quit worrying about small things, Have you considered that?
I think you will be happier if you don't do that.
Here's what I think you should do.
Instead of sitting at home and and thinking no one wants to hang out with you I think you should not sit at home and and hang out with someone that wants to hang out with you.
Try that and see if that helps and good luck.