Marki,
1. blaming yourself only makes it worse. Don't focus on that. Don't kill yourself over that.
2. You say that you don't know how to be happy. Actually, you do know how to be happy. Let me give you some practical advice.
1. Physical Exercise. 30 minutes a day will release chemicals in your brain that will make you feel better. Walking, biking, swimming, aerobics, dancing, weight training....
2. Focus on your interests. What are your hobbies? WOrk on them. For example, my hobby is 'self development'. I like to find ways to make myself healthier than apply it. I also like to teach others what I learned. I am doing that right now aren't I ? I'm sharing my ideas and knowledges. That's a hobby of mine and it makes me feel better about myself. I'm also helping myslef by doing this. I learn great things.
3. Love yourself. instead of put-downs tell yourself how great you are, how beautiful you are, how sexy you are, how cool you are, how 'groovy you are', how great of a listener. Make a list of all the positive qualities and skills that you have and read it allowed to yourself each day.
4. Positive Language. Turn everything into a positive. It's easy and you're brain will thank you. I've done it and it's working.
5. Choose how to respond. Steven Covey, from book, '7 habits of highly effective people', states that 'between stimulus and repsonse...is our freedom to choose'. CHOOse to intrepret every situation as positive, choose to interpret everything as wonderful and interesting, choose to interpret everything as an interest challange that will develop your potential and create a new and better person in you
hope this helps