Why Is It So Hard To Change?

I remember my New Years REsolution for 2011 which was to make myself happy. I know it's a lot easier said than done but after two extremely difficult months I did it. Now I find myself with the same New Years resolution and I'm finding it a lot harder to accomplish. I try to lose weight, seeing as that's the root of my problem, but I can't push myself to do anything. I look at myself in the mirror and absolutely despise what I see looking back at me. For years I've been dealing with my weight and now it's come to a serious point where either I lose it and feel absolutely amazing or I stay the way I am and gain pound after pound until I can't get out of my bed. I know I should lose it and feel amazing but what if I can't? What if it's too hard and I end up miserable like I am now? Will I put my hands up in the air and say at least I tried? Or do I wallow in silence and lose everything I've worked so hard to achieve?
I'm 21 years of age and I can't even motivate myself to be happy. I have amazing friends and family and not to mention an unbelievable boyfriend. I have to do this for them. I don't want to feel like this anymore. It's bringing me back to my dark days and I can't go back there. God knows I can't and won't allow it.
I know you guys probably think I'm crazy but seeing this all laid out. I have no other choice. I think I'd rather say I tried than not try at all and absolutely without a doubt lose everything like I did before. It's time for a serious change no matter how hard it's going to be I have to and will do this.

Thanks for reading guys and I will give you an update soon!