Just keep doing your splits. It's sort of like trying to nail a simple skill - the only way to really get it is to keep practicing. When you stretch your splits, hold for at least one minute (preferably two) on each side. Push your shoulders back so that you aren't resting on your hands, or hold your arms over your head (although if you're holding for two minutes, this may get tiring). If you can't reach the ground when you put your shoulders back, and can't keep your balance, stack books or similar to hold on to (we use paralettes at the gym).
Pike stretches are also helpful for front splits. You can do oversplits if you have a comfortable way to do them at home. You need them in two weeks? If you're not close-ish right now, I don't know if you can get them by then...it takes time, because your body needs to adjust to an unnatural position like the splits. Your body doesn't need to do splits in the normal world, so it's not designed to be able to, and it resists attempts to get to split.