You can make toast on any concentrated heat source. I once heated pizza on an iron. I've also heated pizza on the hot part of a coffee machine beneath the pot.
Probably not the healthiest, but I like to spread butter and sprinkle sugar on top of a piece of bread or toast when it's all I have. Every once in awhile doesn't hurt and it satisfies my sweet tooth.
Or if you had an egg, you could do french toast. Bread and butter can be made into a lot of different meals with just one or two small extra ingredients.
At least it wasn't a "jam" sandwich. You know? Jam 2 pieces of bread together and chow down. Seriously though, it sucks when the cash flow is a no go. It'll get better OP. Hang in there.
It's worse when all you have is bread and mayonnaise. As someone who had to eat a mayo sandwich for lunch regularly throughout my childhood, I can say that butter or jelly is not that bad.
If you lived in the US, I could teach you how to shop to get a week's worth of healthy and filling food for less than $10, but I'm not sure how grocery sales and coupons work in Russia. I hope things look up for you soon.