Freecycle is a good way to get things gone without throwing them but if that doesn't work for you for some reason - Throw it.
I hear you about the waste aspect, but...the waste is having bought it in the first place. It isn't doing the environment or anyone else any good sat in your home and if you're not going to sell or donate it, throwing it out is a better, and less wasteful, solution than drowning in stuff.
Having too much stuff in your home makes you wasteful. You can't find things you actually need when you need them and you buy them again. The cost of maintaining a messy house is higher than maintaining a cleared one.
So hire a skip or just fill your bin each week. That's fine. The key to being environmentally sound is in not buying more. That is likely going to be the tricky part.
So set yourself a rule that you can't buy anything you don't have a space for and you can't buy anything on a whim. If you have a hobby that tends to accumulate stuff (reading, knitting, gardening, park run, whatever) Make a space for it (two bookshelves, a cupboard, half the shed, a drawer and corner of the garage, etc.) and once you've used that space in an organized way, you have to get rid of some stuff before you can get more. Also, if this is part of your downfall, don't accept tat of people that they don't want anymore.