To go or not to go!

We've had some layoffs at work, actually quite a few, and through some magic of fate, bad management or resume, I was spared and allowed to continue the mayhem I usually generate around here. But a lot of my colleagues weren't as lucky and were "let go". This was the first large-scale "layoff" I've been through in my years of being employed. Today, I got to thinking what exactly my feelings were about the whole event and here are a few conclusions...
1) My primary feeling is relief that I still have a place to go to where they appreciate my work and the hours I put in. I like feeling useful and that I have a purpose everyday.
2) Since I was the last person hired in my group and not the one to go, there's a sense of achievement that the powers that be really recognise my skill set and want me to hang around.
3) Tremendous relief that now i don't have to go through the whole "H1B to H4" process and the subsequent job search that my out-of-work colleagues are mired into.
4) That continuing paycheck is suuuuweeeeeet.
5) The boredom that i went through being home for a while will not have to be endured again.
Those were just the positive points. There were quite a few negative ones too...
1) I miss my colleagues.
2) I donot appreciate the tremendous workload thats come upon me as a result.
3) The relief at keeping my job is balanced by the fear that the next round may see me being kicked out.
4) Surprisingly, there's a lot of guilt that I was the "one who stayed". I was the last one hired in my group, but others much older and more experienced were let go, and since I even had a nice, cushy, fall-back option if I were laid off, I feel guilty that I wasn't the one to go.
And thats the feeling thats bothering me the most. In the cut-throat world of corporate business, there should be no guilt about being a survivor. Relief and a sense of lightness, definitely, but no lingering sadness or the feeling of injustice done to others. Everyone around me tells me that I should be grateful and happy that I am still employed, but the feeling refuses to go away. I keep thinking any mistake I make now will make my boss doubt his judgement in keeping me on. Unfair on a boss who's fairly competant at what he does, I know, but that feeling is going to weigh on me for a while. Self-confidence crisis, anyone? I know time will take care of that too, but this episode has made me realise how ill-fitted I am to being in any kind of managerial position. I was never the cut-throat, take-risks, overly-ambitious type, but this just added another notch in my intent to stay on the technical track. The term "individual contributer" was made for me, and I think I'll stick to that for a while.