What upgrades to this PC for Helldivers 2?

I just started getting into Helldivers 2 with some friends and I'm finding it a blast but I've been having some serious FPS issues which might have something to do with my current build being a bit outdated. Originally bought the PC off a friend of mine in 2018 so I'm not super familiar with the original building of the PC but I know details to understand it. Any help is appreciated!

Mini ITX build btw

CPU: Intel Core i7-7700k 4Core @ 4.2Ghz

Graphics: NVIDIA GeForce RTX 2070

RAM: 2 x 8 GB DDR4

Storage: 500 SSD storage getting a bit full along with 1TB Hard Drive

Motherboard: Gigabyte Technology Co. H270N?

Monitor: Samsung 27" curved monitor 1080p, 60hz refresh

Budget: ~1k-1.5k

Games I currently play: CyberPunk, League of Legends, Helldivers 2, Last Epoch