Please help me! I have a 03 Lexus just all of a sudden no breaks and loud alarm.

Short answer is yes. while you drive the fluid sloshing out of the reservoir may allow air to reach the master cylinder and your brake pedal will feel softer than normal. The BRAKE light and alarm are indicating the fluid level is too low in the reservoir. If you are not mechanically inclined, TOW it to a shop to have it bled/repaired. here is a list of certified shops in your area: http://repairpal.com/lexus-within-10-miles-of-lithonia-georgia-30058