you're definitely going to need a bigger dehumidifier to bring your humidity levels down. Get one with the ability to attach a hose so you won't have to worry about it filling up and having to empty. if you can't find a way to keep your humidity low, you're going to get bud rot again 100%.
If you can't fit it in your grow tent, then put it right outside your intake vent to dry the air before it gets in the tent.