i'm not a scholar to give a fatwa, but all i can say is sister instead of inviting hundreds of people for waleema with haram money, you can as well give invite few people with what you have in HALAL.
This is an important step in your life, you are starting a new phase of life, do you think you should start it with something which is not halal?. there are lot side-effects of using non-halal. Your dua will not be accepted if the food you are eating is from non-halal resources. There is no barakah if your earnings are not halal. The sense of contentment will not be there as you have found a easy way to make money and for which you will be more greedy.
JAK