Sharing a closet

Ugh so I’ve spent my entire day, well actually the last 5 years trying to organize and fit everything into my closet. It wasn’t always like this, when I moved into this place with my son I had an entire walk in closet to myself. It was amazing, I always had somewhere to put my clothes and I always kept it nice and organized. Well when my boyfriend moved in 5 years ago he took over about 75% of my closet and an entire 2 dressers. One upstairs and one down. Now I have literally nowhere to put my things. I long for that nice clean spacious closet to put my stuff away in but that’s a thing of the past now I guess. Any tips on how to organize my clothes with such little space. I literally have a 4 ft rod plus 3 small shelves to put my things on now. Ugh 😑.