The LD50 for acetylsalicylic acid (aspirin) is 1750mg/kg. LD50 is the lethal dose in 50% of the population based on calculations. Normal aspirin comes in 325mg per pill. It would take a lot of aspirin. Like most medications, Aspirin is not something that you want to take in large quantities. Aspirin decreases prostaglandin production, which is responsible for inflammatory responses (causes inflammation) which is why it can be used to relieve pain. Prostaglandins are also responsible for protecting your stomach from the acidic content. If you take a lot of aspirin it can break down that protection and can lead to an ulcer, which could lead to internal bleeding. Also, aspirin has anti-platelet activity, which means that your body could lose it's ability to clot blood. Losing this ability means that if you bleed from a cut (or ulcer) that your body will lost it's ability to stop it.
I'm not sure why you took that much aspirin, but for whatever reason it was a poor choice. If you were bored and had nothing better to do, or worse, if suicide was the motive I recommend that you see a therapist to help you. There are ways of coping with these feelings to make your life better and enjoyable.
If you were taking this much aspirin because of a headache, pain or other medical reasons I recommend that from now on you consult your doctor or a pharmacist about how much to take before you take too large of a quantity again.
If you have any other questions feel free to email me.
PharmD Candidate. http://msds.chem.ox.ac.uk/AC/acetylsalicylic_acid.html