ya... u can jungle very sustained as Nasus. I use the very same build but instead of a Philosophers stone and boots, I build my Cloth Armor into razors then Wrigle Lantern. After that, i finish my same build.

Of course take different summoner spells in this build.

The runes I use here also work well in jungling.

my items are only what i prefer so dont feel like you need to stay directly to build. I prefer you go off and try new items and see how they work for you.

In this build i chose 0 21 9 to help increase my tankiness in lane and be able to take inevitable harass that puts you into turret hugging and helps you stay in longer.

For my runes i chose a mixture of damage and tankiness.

Marks:
I use 3 magic pen reds to make sure that your ultimate can neglect some magic resist and deal full damage.
I use some 6 Armor pen reds so that your auto attacks can deal more damage to turrets and tanks.

Seals:
I use all armor seals to make your self take more damage in early game and if you need to pop in jungle for any reason.

Glyphs:
I use magic resistance glyphs to be able to take magic damage harassment from a range character.

Quintessences:
In this build I use health Quintessences to increase health for obvious reasons... lol

If you prefer to be less tanky in matches, take mana regen Seals and Cooldown Reduction Glyphs

Most important for this build is the need for Nasus to be able to last hit minions with Q skill just as usual. The extra 3 damage will be able build up over time, giving you a great late game. Depending on how much you are pushing/ being pushed and getting the permanent dmg., you might need to call a gank from your jungler to help kill/assist your opponent laners or atleast give you some time to solo farm without pressure.
Being a solo lane tanky character such as Nasus helps you take on many carries and insures that burst from characters wont take you down too far(unless fed). You want to start with Cloth Armor, 3 health pots, and 1 mana pot for the majority of the time when you are required to solo land. Armor helps you take less dmg. Health pots are there to keep you topped off in hard lanes on in a fight giving you an edge. Mana pots are the weird ones. I prefer to use mana pot earlier on to have enough mana to increase permanent Q dmg whenever needed. If for some reason you are not having that problem, i advise keeping that mana pot especialy to make sure if your Jungler comes to gank, you will have enough mana to use all abilities.

If for some reason you are facing a counter of Nasus such as Corki or Ashe or just made mistakes, it's okay. Nasus, thank god is not dependent receiving early game feed or getting kills. He is a champion who can come back just by switching up which items to get first.

In mid game, if early game hasn't gone well, or if you expect your team is not going to have a good late game, make sure to build tank first. Get Philosopher stone or if you want, a Heart of Gold to help sustain yourself and live in lane. If you encounter an unbalanced team with alot of Ap damage, be sure to get some sort of magic resist item such as a Spirit visage or in a worst case situation, a force of nature. Much like Other tanks, if there is a high AD damage team make sure to build a Thorn Mail. But! thornmail doesn't do anything unless they have health to take out. Make sure to get a health item such as Kindlegem or Heart of Gold before you get it. If you play according to your enemy, there is a high chance that you will come back late game since they couldnt take you on earlier.

If the reason you aren't doing well is you, either change lanes and build full tank or try and hug turret and build confidence and harrass for a bit with E skill. Nasus is easily able to be killed if he isn't tanky or low level so dont play stupid and you are pretty much gaurenteed a late game.

If you are keeping your opponent laner from being able to farm, rank up kills, or just have a higher level and damage than the opponent, this is what I advise reading.

I prefer to build Ninja Tabi boots at first back and if enough gold, buy a philosophers stone for the extra gold and regen for being in lane your lane for a long time. This helps to keep you in lane longer than your opponent. As soon as you have anywhere from 1450 gold to 2300 gold find a time to go back and buy a sheen. Sheen is very necessary for a high damage Nasus. this makes your Q skill deal more damage. This though, makes Nasus do the most possible damage by rushing in, using W skill and making sure you auto attack before using Q skill so you maximize your damage. From that point, Sheen and Phage are able to slow the opponents while maximizing damage before Trinity Force.
By the time you get Trinity Force, Boots, and Philosophers Stone, you should normally be around level 13 or 14. If you have these items earlier though, I would advise to build according to your team and personally to deal more damage or move to full on tank. If you are getting these items at a later level, It would be smart to build tankier and instead of building a Tri Force, take Phage and make a Frozen Mallet, or skip Trinity Force and build straight tank immediately going and building Soul Shroud.

If though you are doing well or haven't seen their jungle for a while, make sure to ward atleast one place in the river. Make sure you check other lanes to check MIA's when not called.

Nasus is always going to be able to deal major damage, but you need to put yourself in the right place at the right time. He is going to fall in behind the tank to make sure he assures his position to pop ultimate and be able to deal damage to all people. Also, place E on top of a place where you expect their team to be for a decent amount of time. If there isn't a tank and you havent taken the split the ability of tank with another AD or hybrid tank dmg character, be sure to run in, slowing their heavy AD dps. As soon as they attack you, not just harrassing, drop E and Ultimate then start Q skill shooting on their Squishes. If there are other tank positions you like, go ahead and try it out and try and tell me how they go.