I suppose that this is traditional Monster Hunter fare but some of those boss fight actually nerve wrecking long... I just had a 40 Min fight against Giggnox (and lost...) and I actually feel tired. I suppose that once you get used to them that you will be able to kill them before you start wanting to strangle yourself with the nunchuck cord. After all i can beat the bananasaurus pretty fast now but even that took me quite some time to get there.
 
Monster Hunter sure is... special. 
 
Talking about special, here is my current gear:
 

Wow, if I had a 40 minute battle and lost I would probably shit everywhere and cover myself in it.

" What if i told you that you lost that 40 minutes fight because you ran out of potions and you were stuck in a corner? "

Sounds awesome, can't wait to get it.  The thought doesn't deter me in the slightest.

Gigginox is significantly weakest to fire and you're using a Ludroth water-lance. Get your hands on some fire weapons, duder!

You need to evade more. Try a different weapon if you can't do it with the lance. A great sword is a good choice for most early monsters (not the Barroth, what a bitch, it took me three tries) from what I've seen, as long as you don't get impatient. With it, you need to dodge a lot and only strike when you're sure you have time for it, but the power of the great sword makes up for that, especially if you get charged hits in. I never take so many potions as adviced, I only do with 10 mega pots. I did regret it a couple times but I figure if I need to use so many I'm doing something wrong that I need to improve than just fill my inventory with stuff. Anyway, just watch the bosses' movements carefully, you can easily tell what they're about to do with the exception of some moves so then just roll/dive/whatever out of the way, and hit them while they take the time to turn around and face you again (or keep your distance if they seem like they'll do a sweeping move instead). Perhaps you're mostly using the block with the lance due to the slowness but you should still mostly evade, as blocking often isn't that helpful, since it leaves you in front of the monster still, ready for it to do another attack. Just run around the enemies, so that they do moves that miss, and you get a window to hit them before they refocus. Just like they can hit you during an attack animation, or after a miss if you're not careful, you basically do the same.

 Unless a Rathian pops in for Gigginox tea, you'll be fine regarding any fire damage. Keep your guard up and happy hunting!

" You need to evade more. Try a different weapon if you can't do it with the lance.
 
Perhaps you're mostly using the block with the lance due to the slowness but you should still mostly evade, as blocking often isn't that helpful, since it leaves you in front of the monster still, ready for it to do another attack. Just run around the enemies, so that they do moves that miss, and you get a window to hit them before they refocus. Just like they can hit you during an attack animation, or after a miss if you're not careful, you basically do the same. "

Water is probably not a good element against a Giggi... At all.
 
I found my first fight against him last the usual 20 minutes (I think I used a hammer in my first try, I've killed him with a LS, GS, and a hammer so my memory is a bit blurry).
 
He actually isn't that hard to fight once you get used to his patterns (Which was confusing for me at first, but gotten the hang of after 10 minutes). 
 
BTW if your walking with your weapon out, your probably not going to do enough damage, the Giggi doesn't stand still all that often, leaping around you and what not.  
 
BTW if you're getting poison often you should change your weapon to something that doesn't have you facing the monster. It's easy to never get poisoned if your on it's side, since the only poison attack that might hit you is the poison slam.

I've ended up beating him yesterday. It still took me 25 minutes and i used some explosive kegs to set it on fire every now and then. The poison still was a huge issue. Him leaping all over the place was indeed extremely annoying with the lance. 
 
At the end i also realised what i was poking in with my lance, which was odd...
 
Well it is up for the next monster. I'm thinking of taking Diablos down now but i'll need to stock up on those sonic bombs since they appear to hit him knock out every-time he is digging.

" Wow, if I had a 40 minute battle and lost I would probably shit everywhere and cover myself in it. "

Ok so Diablos was fun... I had to bail out in the last 5 minutes because he just wouldn't die... 
 
Why the that timer even there? It is extremely discouraging. I would have preferred if they would have put in place some ranking system based on how long you took to beat a level and that you needed to get an overall grade in that quest set to unlock the next set of quests. At least that way players wouldn't be forced to play aggressively all the time and it would be possible to get new gear. 
 
Haaa Monster Hunter...

i just beat diablos last night actually, my humble tip: bring as many sonic bombs and traps as you can. when he's raging start using pitfalls and you'll get a lot more hits in than a shock trap. also i used a long sword and just kept getting right under him and hacking away. ended up doing really well and only used 3 mega potions along with the first-aids.
 
it was the last the fight of the night and i figured, what the heck, i'll try this cheap ass monster again. haha sure enough.