What you want, if at all possible, is an IND-CPA (or, preferably, even IND-CCA2) secure encryption scheme. Such encryption schemes are by definition probabilistic (and/or stateful), so that even encrypting the exact same plaintext twice will produce completely different results.
Conveniently, there are plenty of block cipher modes of operation that provide IND-CPA security, as well as authenticated modes that even provide IND-CCA2 security (which includes resistance to active forgery attacks where an attacker may modify encrypted messages and observe the results of attempting to decrypt them). Triple DES can be used with most of these modes — but you really shouldn't be using it nowadays, since AES is both faster and more secure.
If you absolutely need your encryption scheme to be deterministic, so that the same plaintext always encrypts to the same plaintext, the next best thing you can have is DAE security. It's basically the same as IND-CCA2, except that because it's deterministic, an attacker can obviously tell if two encrypted messages have the same plaintext or not.
The first and most popular DAE-secure encryption method is SIV mode, although there are also newer and potentially faster schemes like GCM-SIV. All of these are designed (and standardized) for use with AES; while you could in principle used them with TDES, that would be less secure (particularly due to the smaller block size) and generally pointless.
Conveniently, SIV and other DAE-secure encryption modes have the useful feature that, if you include a unique nonce as associated data with every encrypted message, they become fully IND-CCA2 secure, and still remain DAE-secure even if you accidentally use the same nonce twice. This "nonce misuse resistance" is a very handy safety net to have, and IMO is a good reason to use AES-SIV (or AES-GCM-SIV) whenever possible.
Finally, I'd like to note that your description of your attempts so far doesn't really fill me with confidence that you know what you're doing. (That goes particularly for the fact that you mentioned using TDES, but not which mode you're using it in — that's kind of the crypto equivalent of saying that you're driving a 4-cylinder internal combustion engine from 1995, but not specifying whether it's in a car or a motorbike or a lawn mover.)
If all this talk of "nonces" and "modes of operation" and "IND-CPA/CCA2 security" goes straight over your head, I'd suggest either picking up a good introductory crypto book and/or just browsing this site until it no longer does.
While there are nowadays some relatively "foolproof" encryption APIs like NaCl
crypto_secretbox available, you do still need at least enough basic crypto knowledge to understand the terminology and to be able tell a secure and well designed system from complete snake oil. Or you can just hire someone who does understand all this stuff to design your cryptosystem (and someone else to review it — which you really should do anyway).