I have a 100 character text message and I want to encrypt this message with my bitcoin "PUBLIC KEY" and decrypt it with my private key in Javascript Are there any javascript libraries that can encrypt a 100 character text message using your bitcoin public key, but only be able to decrypt it with your bitcoin private key? 

I'm looking to create a web form that can encrypt the form values using only your bitcoin public key. And on the other end when received it can be decrypted with the private key.
You could use something like this eccrypto (Do your own research on the security of this implementation). Also, doesn't appear to allow compressed public keys. Update: It now supports compressed keys as of v1.1.

index.js

var crypto = require("crypto");
var eccrypto = require("eccrypto");

var privateKey = new Buffer("c337ded6f56c07205fb7b391654d7d463c9e0c726869523ae6024c9bec878878", "hex");

//var publicKey = eccrypto.getPublic(privateKey);
var publicKey = new Buffer("04730a151f545f5dcdb1c6d99fb1251f5c70f216f39ba2681bcf10db16bd582e6720bc881d51f25ffbe961df6a0af24a9d39a4db3d86a7f6b3f9bf4eaac0e4006b", "hex");

// Encrypting the message for B.
eccrypto.encrypt(publicKey, Buffer("msg")).then(function(encrypted) {
    console.log('Encrypted message ' + JSON.stringify(encrypted));
  // B decrypting the message.
  eccrypto.decrypt(privateKey, encrypted).then(function(plaintext) {
    console.log("Decrypted message: ", plaintext.toString());
  });
});


Output

$ node index.js
Encrypted message {"iv":{"type":"Buffer","data":[204,13,168,25,80,255,9,233,111,60,165,204,180,126,53,65]},"ephemPublicKey":{"type":"Buffer","data":[4,192,3,65,241,134,65,186,52,52,250,61,208,189,216,167,122,206,156,152,27,173,69,152,37,138,164,5,54,189,227,88,37,243,220,183,22,204,235,37,212,110,207,66,225,244,25,92,69,223,247,175,218,228,134,210,247,190,211,248,239,77,183,21,36]},"ciphertext":{"type":"Buffer","data":[75,104,205,95,93,108,18,50,220,120,164,224,42,214,75,28]},"mac":{"type":"Buffer","data":[63,243,230,143,99,187,246,241,194,10,247,215,188,163,82,98,140,15,186,158,58,207,170,49,230,143,26,17,117,248,195,143]}}
Decrypted message:  msg