Gameboy multicart help

[FusionFountain]

So I've had my gbc for a little bit an I use it at school frequently, so to keep the games from falling out the only pocket to use is the cell phone pocket which now won't fit all the games. So is there a gbc gaming cartridge multiple card I CPUs use to hold a large amount of games?
The only other way is buying a $70 card with some of those games and I'd rather get one I could make a custom one myself with the games I already own and just add onto it

[cross]

No, the largest one out there is 64mb memory only and not guaranteed to work with all games.
If you want links reply