Hi Danzer. I know exactly how you feel. For all of my life, up until around October 2005, I was saying the exact same thing... I mean literally, I could have written your post, and I have written many similar things on other boards and a million times in my journals/diaries over the years.
The really frustrating thing is that I don't know what to say to help you, because you're right, you know everything you need to do. You know that it really is as simple as doing it. You know it all and still you don't do it, and then you feel bad. I know. I've been there. Looking at it from the other side of the fence (having successfully "started") I know just how true all of the advice was that I received, about just doing it and that I could do it and blah blah blah blah blah. But to impart that to you in a meaningful way... I don't know how.
I'll tell you a few things that really helped me. First of all, you say "and it's not like I can ask for help, because this is something I myself need to do." For me, asking for help was key. I was ready, I knew all the things I had to do, but I needed support more than I ever realized. I couldn't go to my family or my friends... I just didn't feel comfortable. I come across as someone who is strong, and admitting weakness like that was hard for me. Plus, telling people I was trying to lose weight had led to me giving up before. So I searched the net for dieticians in my area, and I found a woman who was helpful and supportive, and I still meet with her once a month. I thought I needed a shrink or something, but really all I needed was the idea that I was being held accountable to *someone*... and I needed someone who could point out to me that I could do it, and that I WAS doing it, and that it wasn't the end of the world if I ate a piece of cake or something. She counters my inner voice who tries to bring me down. And surprisingly, that critical inner voice has become weaker and weaker since I've stopped letting it control me.
Another thing that helped me was stopping "starting". I am a perfectionist and it used to be very difficult for me to stick to any kind of diet plan for more than one day, because I would sabotage myself thinking "I'm gonna fail on this eventually, so I might as well just stop now." I would start journals intending to record my weight loss journey and then abandon them when I "failed", starting a new diary a few weeks or months later. But I've realized that there is only one journey! I have one journal now where I write every so often, whenever I feel like it, about my weight loss issues and about whatever else I want. And it represents that this is one journey that I'm on. Even if I give up eating healthy and pack on the pounds for ten years, and then decide to lose weight again, it's still part of the same struggle. So there's no more angst about getting started--I already started. If you start eating healthily tomorrow morning, and you "give up" by supper and eat a whole pizza, you've still started the journey, and you're still on the journey, and you won't be "starting" again the next morning but just continuing and learning as you go.
Anyway, I don't know if any of that will be useful to you... this process is so personal. But I want you to know, you said exactly the same thing as I've said, I've been there, and here I am now. And if I can do it, you can do it.
I just need to keep on keeping on...hehe. THANK YOU!