All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
We have already issued Fatwa 84996 clarifying that it is forbidden to work as a waiter serving intoxicants (all kinds of alcoholic drinks) and there is no doubt that the money you earned by serving intoxicants are ill-gotten money because the salary of carrying intoxicants for people to drink is not permissible for the worker if he did so while knowing that it is forbidden. Therefore, he should gift it in charity and not spend it on himself. However, if you had already estimated the amount of that salary and given it out from your lawful money, and spent it on the poor, then we hope that you did what is required from you and you are acquitted from sin.
For more benefit on how to get rid of ill-gotten money, please refer to Fatwa 83894.
Moreover, you are obliged to repent to Allaah by regretting doing that job and be determined never to do it again.
As regards whether or not that money has an effect on your prayers …etc, then there is no doubt that ill-gotten money has an effect on the person who earned it, in a way that there is no blessing in it and that it prevents his supplication from being answered and so forth. The Prophet mentioned (the case of) a man who has travelled a long distance – unkempt and dusty – and who raises his hands towards the heavens and supplicates: 'O Lord!' 'O Lord!', while his food is ill-gotten, his clothing is ill-gotten and he is fed with ill-gotten money; then the Prophet said: "How could his supplications be answered?"[Muslim] Moreover, it is reported in an authentic narration that "Hellfire is more appropriate to consume the flesh that is fed on ill-gotten money then." [At-Tirmithi]
Besides, it is reported in weak narrations that ill-gotten money is a reason for the rejection of good deeds like the prayers and other acts of worship, but the fact remains that whoever repents, Allaah will accept his repentance. Indeed, a person who repents from sin is like the one who has never sinned. Therefore, have glad tidings since you repented to Allaah.
Allaah Knows best.