Pokemon Silver on Gameboy Color not working correctly! ["Solved"]

I have had this problem on my Pokemon Silver cartridge I found on eBay, I've tried everything that I've could and had no success.

Problem:

Whenever I start the game it boots up like normal. I select new game and the intro plays except after choosing the time the screen goes black and sometimes reveals the bottom left part of the screen before it froze for about a half a second. After skipping through a few of the text messages (probably starts when the name your character screen appears) it either shows a white screen, throws up a bunch of data, or restarts the game with a glitched color palette (sometimes rare.)

What I've tried:

I have tried everything, I've tried blowing into the cartridge, cleaning it with a q-tip, and I have tried checking the battery and the battery was brand-new. I've also tried cleaning the Gameboy Color inside and replacing the batteries.

If anybody can find a solution that would be great. There is a chance though that It might just be corrupted.

EDIT #1:

Loaded it into my GBA. The game plays normally except for battles and battle or battle like sprites (such as Professor Oak in the beginning) are garbles, static things look like they're corrupted. Keep in mind the cartridge was acting normally before this even became an issue. Battles seem to give the enemy and your Pokemon infinite health after using an attack, making trainer battles impossible. Other than that runs completely normally and exactly like the original. I also made sure it was the original by watching some gameplay videos of it.

EDIT #2:

I Looked inside the cartridge to see if I could see any problems. One thing that I didn't notice at first was that the battery inside was small and didn't fit the battery outline. So I compared it to the other batteries that I have and it seemed to fit perfectly in the outline, so what I'm thinking is, the battery is small and causing some problems. So once I have the tools to desolder and solder in the new batteries, I guess I just have to wait.

EDIT #3:

No success on changing the battery. Same results. So I guess I’ll just have to buy a new cartridge. Thanks to everyone who tried to help.