So if I don't know what's on the paper because no one has made sure that I do then I still can be upheld on what I signed but if the guy who gave me paper to sign doesn't know what's on the paper because he didn't notice my changes then he can't be liable?
You have a duty to read before you sign a contract. In this case, they can claim you tricked them into thinking you'd signed the form contract, and that they relied on that agreement when they provided you care. IANAL, but I suspect you will lose this unless you can show that the staffer accepted your changes knowingly.
I'm still not an expert on contract law, but I would suggest that yes, that's the case. The law isn't necessarily perfectly symmetric between the original text of the contract and handwritten alterations put in at the time of signing.