And you're asking us to go over the same ground that we've already covered.
If there's a valid early notice / liquidated damages provision, you can be required to give up to 60 days notice or pay liquidated damages of up to two months rent. If your landlord attempts to misapply the law, demanding what amounts to four months of rent for early termination, nobody here can promise that you won't end up having to deal with your landlord's effort to bill you, sue you, and/or make a report to a credit reporting agency claiming that you owe money.
Given what you have told us, if there was not a proper addendum, your landlord should not be able to enforce a liquidated damages / early termination clause in court -- but it sounds like you want to apply that provision, so if this matter ends up in court you would have to weight the strategic advantages of trying to defeat the clause. If you vacate on less than two months notice and the landlord is able to replace you within the total two month period, you could try arguing that the landlord cannot enforce liquidated damages due to his statutory non-compliance, and that you should owe no more than the landlord's actual damages -- the reasonable cost of re-renting the unit and rent for the period between the end of your tenancy and the date the new tenant took occupancy.

