I agree with what @neighboursmustliveon said above, @Notaskingmuch.
But I voted that you are being unreasonable. I did so because you didn't tell your friend acquaintance why you were using the food bank when she had either seen you, or you had told her that you do so.
I know OP that you shouldn't have to, and indeed you don't have to, tell anyone anything - apart from the people running the food banks - about why you are using the food banks. However, if you, very reasonably IMO, don't want people thinking erroneously about why you are using them, then I'm afraid that you will need to explain to the people who's opinions you do care about, why, even though you have a comfortably well off family, they refuse to help you.
I can only think of one reason why I would not help you OP if you were one of my family members, and I could afford to do so, and that would be if I had been strongly advised by trusted experts, to treat you with "Tough Love". I am sure you know that the times when "tough love" is usually needed is when a family member or loved one, has some kind of self destroying behaviour/addiction, such as:
Drug addiction, or
Alcohol addiction, or
Being addicted to buying unnecessary, and ultimately useless objects etc, even though the addict cannot afford to do so.
These addictions, and probably several others as well, may ultimately and tragically, lead to the addicts death, so if someone is guilt tripped into helping their loved one in their addiction by either giving them money directly, or helping them pay their bills, or by even buying food for them, then the person helping them could actually be helping their loved one into an early grave.
We cannot know your personal situation OP, but whatever it is, I do feel very sorry for you. If your family are deliberately not helping you because they are just horrible people, then again I do have a lot of sympathy for you. If you do, or have done, everything in your power to afford to feed yourself, then as I said at the beginning of my post, it may unfortunately, but probably, be in your own best interest, to tell the judgemental people in your life, the truth. Of course, you are the only one who knows the whole truth about your situation, so all I can say is that I wish you the very best, and I hope that you make the correct decisions for you xx