EK shadow nova build advice/help needed badly

Link to my tree: https://www.pathofexile.com/passive-skill-tree/AAAABAYBAAMeBbUHHg2NDdEOSA-rEJIRLxGWFr8Zih9BIuoj9iSLJP0mlSoLKjgwfDIBMjIzkjY9QxNJUUp9TZJOKlBCUUdVS1uvXfJh4mJaYqxjQ2SdZ6BqjGyMbWxwUnBWdf2BrIRvhMWHdonTjDaNfY2_j_qVLpcGmhObtZ2qotmjirDYshm1SLmTu-O8b8MJwzrEosgUy73PetQj1ELZhtvU35jjhOOf5oHnVOd06NbrY-v17g7w1fId9W_8xf66_94=?accountName=Gold3h&characterName=shatteringsnips

You should be able to view my gear as well by clicking on my character Shatteringsnips. It's public. https://www.pathofexile.com/account/view-profile/Gold3h/characters

I'm in dire need of help because although I'm enjoying playing the build I'm kind of performing really poorly in higher tier maps. Actually really anything over like 5 or 6 starts giving me serious problems... and It's not really because of the AOE (trash) mobs.. it's typically orange or yellow enemies that take me too long to kill due to my single target being so poor.

Is there an alternative skill to EK that I need to be using for single-target encounters? I don't really have the sockets to work that out.

I'm working on getting my Belly of the Beast chest piece 6 linked. I do have 6 sockets on it but I've blown through about 200 fusings trying to get them linked so far. No luck. But that should really help my survivability.

My damage seems alright... I may want to utilize fury charges since currently nothing I'm using generates ANY but I'm not sure how I'd want to generate them.

I'm looking for fast clear speed which is why I chose this build, and I understand I can't be a jack-of-all trades murdering single target fights and flying all over the place with this type of build

Any suggestions right out of the gate for anyone? I don't have issues on lower tier maps. I clear them pretty fast. I use flame dash as mobility but it feels slow sometimes.. not sure how to make it much faster. My main source of life comes from my leeching with Vaal Pact and some leech from Lightpoacher. Lightpoacher also hits pretty hard for me.

I was originally following a build online and sort of mixing it with Zizaran's older EK build but I'm not the most experienced PoE builder so I potentially effed something up. Or maybe it's my gear?

Any help is greatly appreciated.. I hope I gave enough info and was clear so that I can receive some help. Thanks.

I think you should get a 5-link inpulsa and use EK as your main skill for mapping and put GMP, physic to lightning and control destruction into your lightpoacher. Also get more crit on your jewels and drop vaal pact cuz you're not using either warlord's mark or anything to leech (your life leech node on the skill tree only works for attacks, not spells I think). And drop 1 of your daggers and use a shield instead since you don't have any dual wielding nodes.