As to the current bike, find a donor bike and use parts off that to fix up your current one. Size won't matter as long as the components will work.
Add a front derailleur if needed to help keep the chain on the chainring if nothing else will work.
If time and need are a greater determinate then put the current one aside and shop for something new or used that will meet your needs and likes.

And don't forget to ask the shop mechanics and staff if they know of any inexpensive used bikes that you can buy/barter/trade for to get you by until your funds arrive for the new bike.

Them's my three cents worth of comments.