Unfortunately LLMs need a lot of VRAM. You could try using koboldcpp, it runs on the CPU but let's you offload layers onto the GPU. That way you might be able to stay withing those 4gb even with larger models.
Edit: I forgot to mention there's a fork of koboldcpp with rocm for AMD cards, which is about twice as fast if I remember correctly. Only relevant if you have an AMD card tho.