Honestly I'm just about done with my current setup. I've been trying to get some decent shots of my kids with the kit lens that came with my Nikon D7500 and I am just so fed up with how flat and soft everything looks... its like no matter what I do with the settings the background just wont blur out properly and everything looks kinda muddy? I have my daughters high school graduation coming up in three weeks and I really dont want to ruin the photos because I was being cheap with glass. I've been looking at some primes because everyone says they're sharper but I'm getting so overwhelmed with the options. Do I go for the 35mm or the 50mm or is the 85mm better for portraits? I've heard the 85 is the king but I'm worried it might be too zoomed in for indoor stuff.

My constraints are:

• Budget is strictly under $550 because thats all I saved up
• Needs to be fast enough for lower light since the ceremony is indoors
• Must work well on a crop sensor (DX)
• I need it delivered to me here in Chicago by next weekend so I can practice

I really just want that professional look where the subject pops out and the background is buttery smooth. Is the Nikon 50mm f/1.8G enough or should I be looking at Sigma Art series or something else entirely? I dont want to waste more money on stuff that doesnt perform...