Advice needed

We are traveling to Japan for the first time and need help deciding the best order to travel to each of our destinations and whether or not we really NEED the JRpass? We are on a tight budgetand that is a large expense, but worth it if it would be more stressful and just as expensive buying separate tickets to each area. We are going for 18 days total, arriving in Osaka at the beginning of May. The areas we would like to visit are Osaka, Kyoto, Nara, Hakone, Kiso Valley and Tokyo. We didn't realize planning our trip would be so hard or stressful, any tips would be appreciated!

Over 18 days, you will never make up a JR pass for that itinerary. Travel between Osaka, Nara and Kyoto is very cheap anyway on local trains. JR Pass doesn't cover Hakone, so you would need to pay separate there no matter. So the only big expense you should have is Kyoto/Osaka to Tokyo on Shinkansen.

I'd just get an ICOCA card at the airport and load up maybe 5000 yen for local subway/rail fares. Then buy a regular shinkansen ticket to Tokyo and use Hakone Free Pass for Hakone. WIll be cheaper than JR Pass.

You can adapt from here:
https://www.japan-guide.com/e/e2400_best.html

or here (since you say you are arriving at Kansai):
https://www.japan-guide.com/e/e2400_osaka_16.html

(The major difference between the suggested itineraries and yours is that you are not visiting Hiroshima/Miyajima.)

Planning your trip should be enjoyable too! Have fun

As TW said, the JR pass isn't worth it at all for that itinerary, and even if you weren't concerned about the cost it wouldn't really be more convenient either. Here's what I suggest to minimize stress:

When you arrive in Osaka (KIX I assume,) go to the JR reservations counter (Midori no Madoguchi) in the airport. Since the one in the airport deals with mostly foreigners, you'll be assured to get someone that speaks English. You can then buy an ICOCA card, load it up, get an express ticket into Osaka (they usually have a promotional package if you get that and the ICOCA together, I think) and also your Osaka/Kyoto -> Tokyo Shinkansen ticket all in one go. That's probably everything you need except the Hakone transport (which JR doesn't serve. )

I think this is the deal gfouk was thinking of:
https://www.westjr.co.jp/global/en/ticket/icoca-haruka/

It's a really good deal if you arrive in KIX and need and IC card.

One thing to remember is going from Hakone back to Tokyo you don't need to take the shinkansen. You can take a direct Romance Car Limited Express on the Odakyu line from Hakone-Yumoto Station and then you don't even need to go through Odawara again. It is a little slower than the shinkansen, but doesn't involve a change in Odawara and depending on where you are staying in Tokyo, will drop you off closer to your accommodation.

Good luck!