My employer canceled a self employed contract which stipulated I was entitled to 3 months notice.

My employer canceled a self employed contract which stipulated I was entitled to 3 months notice.  My employer said he could only afford 1 months notice, but could pay the remainder, only if I could work the remaining 2 months notice period over 15 months it would take him to pay me the money owed. He would only be able to afford to do this if I could support his clients who would pay their support contracts and thus he would be able to pay me the money he owed.

Me being a good man not wanting to see him go banckrupt, helped him out and agreed to the repayment arangement.

I have since found out that he did have the means to pay me and he lied to me to get me to enter the new agreement.

My question is; is the new agreement valid as he got me to agree under false pretenses? OR does he owe me the complete amount without me needing to continue to support his clients?