What cpu should i get

I recently got a new nvidia 3050 and a new psu to go with it but i decided to save money and wait on upgrading the cpu (i have 32gb ram as well btw). while playing games my cpu is consistently maxxed out and makes my game freeze and stutter and i think ill just bite the bullet and get a new one. i currently have a Intel i5-9400 and want to upgrade to the cheapest option i can that wont bottleneck my gpu at all. i dont know much about computers but enough to know that this is my problem so i thought i should ask the people who know best. thanks.