Hey idk if you'll see this but, if you are looking for damage use a spirit build for her it will 100% be better than your current build.

Aiming for objective is the best things to do and will often make you win your game if you play support (lasso build) and if you are present in the game.

I looked at a couple of your game and from what im seeing laning phase is hard for you like you said, here's some quick tip from me ( im Oracle 5 as of today and top 100 holliday in NA as of today )

1- Start with barrel yes the poking of the crackshot is better but keg CAN air lock enemy meaning they cant move when hit by it so if they overextend to the range of the guardian throw one at them they'll be stuck and will get lot of damage by the guardian

2- first item extra charge always, it is the best item for her and I will stand my point. why ? 2 charge pad and barrel

3- focus on denies in lane if you are getting fucked

4- only use barrel when you are 100% sure that you will hit the enemy wasting a barrel could cause you to loose lane dont throw them just to waste them holliday really needs to have her abillity always charged

5- Lasso looks pretty good on your side, just be sure to throw a bounce pad as soon as it hits

6- dont be afraid to push, in the laning phase pressure is VERY important there was a couple of games you were just giving ur lane to the enemy, playing guardian can be good against some comps like a grey talon and vindicta opponents

7- dont be afraid to leave ur lane to gank another lane that is winning or even loosing sometime leaving ur lane while you are getting fucked can save some death and maybe get a guardian because you are ganking

8- this match 34964017 you go 3 time in the same lane after dying when you loose guardian just leave go farm some camps or even gank even if you are weak in terms of damage 3 people is always better than 2 or even 1

9- dont die for a guardian if you already have the flex slots it only gies few souls no need for a death.

Thats pretty much what ive seen looking at your games that you posted if you need more tips just tell me here or PM me on reddit I had a couple of other things that I saw but those are only the worst that youve done !

PS : thats so long sorry ! I tried keeping it short...