295?!?!? Dude, you're a monster!!! We need to get that shit up....and NOW!
Rather than spouting off some more advanced things you can do, here are some basic questions:
What type of setup do you have at your place?
Do you have a rack?
Do you pull sumo or traditional?
Do you work 2 weeks on/2 weeks off or do you work every other week?
Do you know how to test yourself to see what stance works best for you?
My initial thoughts without too much information is that your entire back and glutes are fairly weak (relative to your size) which supports the reason as to why your squats are lagging as well. How much can you row (and what kind)? Do you ever do shrugs, croc rows, or olympic lifts? Meaning, how's your trap strength?
I like what MAB has for directly working your posterior chain, but I have a feeling you could see some amazing results from working your assistance work more efficiently.
There is nothing "smart" about a 3rd attempt deadlift.