TBH, I would go see an accountant. The rules relating to payments from trusts and private companies aren't as simple as including the payment in your tax return in their year it was received. There are timing rules and the whole amount may not necessarily be included in your taxable income.
Additionally, (and as stated by @Phalanx922) if the amount was a gift from the parents/in laws directly then it is possible/probable that it will not be taxable to you. Though once again I would go see an accountant to make sure that this is actually the case.
