I seriously doubt you have no coping skills. If you have lived life, the good times and the bad, you HAVE coped through things. You don't always blow up and shop and eat every time anything bad happens do you? REALLY? If so you need help with that and don't worry about your daughter until you get help for yourself. If you DO actually cope with stuff sometimes, focus on what you CAN do. You can turn things around without eating and shopping at times, so keep practicing that.
As for your daughter: I have a six year old daughter. She wouldn't self-soothe with possessions or food unless I gave her possessions and food to soothe her. I don't. I give her hugs, and I listen to her and help encourage her with sincere words to help her work through stuff. As for tantrums-I find not allowing them works best. It sounds harsh to people who don't see it in action. But regarding huge upsets and tantrums as "real tragedies that need soothing" is often the wrong approach for kids. Sometimes they just need to know there will consequences if they choose to proceed in blowing up over nothing, and the problem is solved. I can't count how many times my kids totally forgot they were upset with a calm warning of impending discomfort from me if they didn't cut the dramatics. My 2 1/2 year old needs about 15 warnings a day to NOT begin a fit, and she knows she can't execute one without consequences, so she moves on to playing instead. That leaves the real soothing for the real tragedies, and again, hugs and listening are best for those.
I do model this behavior as well. When bad things happen, I don't blow a gasket and act self destructively. I just wasn't raised that way. I control my temper and act respectfully, which is what I was taught with discipline and love. So my kids see me enforcing the rules I also follow. If you were raised in a way that did not enable you to have coping skills, you need to get to the bottom of that.
I find as adults, people who had parents who curbed their tantrums effectively, grew into self disciplined teens and adults. Of course this can be taken to a negative extreme. But to allow he huge blow outs all the time does not teach kids to control themselves, and self control is a skill we all need in the world to cope well. Future self-control is NOT enhanced by allowing fits and not "making" kids learn to control it. I have friends who say their kids have gotten so much better than when they were younger with fits-which is true-but they're still leagues behind kids who were not allowed to have the fits to begin with.