You do not have the experience to be trying to force feed any animal let alone a frog that is so delicate. Your best bet is to look on craigslist for a new tank that fits the frogs needs. That is what I did, my 30 gallon long cost me $20 and it came with a stand that holds two tanks. Also since you are only 12 you should be talking to your parents about the needs of your frog and do research with them on the proper care for your species, then make a list of the things you need. And ask them if you can do extra chores to make money or for them to buy you the supplies you need. That is what my 12 and 15 year old boys do when they need money for something. Also you should be thinking about getting a frog that is better suited to your skill level. You can buy live plants on-line, I'm pretty sure that Josh's frogs sells a wide variety of live plants with many of them being fairly cheap in price.