I am not knowledgable with this sealant you used, but I would imagine that it is water based. water based or water along will make a very miticulously sanded floor or anything sanded feel rough. The water is getting into the pores and making the wood expand. this makes the wood feel rough.
First, I would have only used water based minwax and you can do this also. I bet steel wool will take the bumps off. Then apply a much thinner coat of the chemical and lightly steel wool again. this should solve your problem. After this, apply a good paste wax and buff it up well.