Taking a picture is a good idea when you're having trouble letting go of something. I got another useful idea from Marie Kondo's book, of saying a thank you (out loud!) to an object before getting rid of it. While purging a ton of stuff before moving, I found this very helpful. I chose to not speak "Thank you" out loud most of the time, but I made of point of thinking of in what way the object had made me happy in the past. For fabric, it could be something like:
..
I found that the element of "honoring" the past positive part of owning the object made it easier to let go of things that the triggered positive memories and associations.

Pack it up neatly in gallon Ziplock bags, mark it 100% cotton quilting fabric, and donate it to a local thrift shop. I had been given a bunch of fabric that I would never use, and it was just taking up space. Assistance League, of which I am a member, runs thrift shops, so that's what I did. It sold immediately, especially these days when so many are making masks.

Don't keep it laying around thinking that some day you'll use it. You will just feel guilty.

I have held on to JoAnn's fabric from the 70s and 80s (and every other kind of fabric from any period) even though I would never use it in a quilt. Primarily, I use this fabric to make FMQ practice squares and collage quilt pieces, but also use random scraps of it in string quilting. As Bonnie Hunter (?) says, 'if fabric still looks ugly to you, you aren't cutting it small enough.' If you have the space to segregate and store it, do so guilt free!

There is a difference between "ugly" - don't like it -

and "poor quality" fabric that would not wear as well as "good quality" fabric.

If one does not like it - for whichever reason it is - there is not much point in keeping it.

I just got rid of tons
 

I sold 4 small garbage bags full of fabric to someone making tons of masks. I work at a quilt store and am now a self proclaimed fabric snob. No more JoAnns or Walmart for me. Easy to say now that I get an employee discount!

Don't toss it. Some one else might make good use of it especially for rug making or crafting and other items that do not require washing or little washing or will be used up.

I do feel that the quilt shop fabrics are a much better quality but I could not afford fabrics from there then and now that I can afford to buy better quality fabrics I can really see a difference in the fabrics. I don't know if I am a fabric snob or not but I don't buy fabrics from JoAnn's any longer. I do understand a lot of people can't afford fabrics from a LQS.

IMO - some LQS fabrics are not LQS worthy.

I feel fortunate that I've found someone that will be happy to get some of what would be the last on my list of what I'd use in my stash. I'm pretty sure my stash will outlive me so if I start feeling like "I don't want to give that up" I go look at the walk in closet full that I'm keeping. Helps me to know I'll never miss it.

Here is what I've pulled so far - now the problem is seeing how much I can pack in a couple of large flat rate boxes.

the "layer cakes" are yardage someone cut into large squares. I picked them up at a thrift store when I first started quilting, and then didn't get to using them and since have bought so much I like better that they've been sitting in a tote for several years now. That's a great thing to rehome. Everything was washed when I brought it home, so it's a bit ravely. The good part on those, the fabric must have been washed before cut as they didn't shrink up when I washed them.