He picked up a hamstring injury in pre-season which hampered his chances of making his first-grade debut.
But the forward battled back to force his way into selection at the Dragons, eventually making his debut against Gold Coast in July.
McCarthy admitted 2016 was a rollercoaster for him.
“It has been to be honest, to come out here with the ambition to play in the NRL,” the Irish international told Love Rugby League.
“I felt like I was having a good pre-season and the feedback from the coaches was great and then the last day before Christmas break I pulled my hamstring, and I think it set me back a little bit more than we thought it was going to.
“And then for the first half of the season I was struggling to get on top of it and towards back end of the season I tried to get my head down a little bit and focus on playing for the club, train well, perform well.
“And then I ended up getting a call up in the NRL which was what the goal was and then the back of the season went really well.
“So even though it was a disappointing start to the season, it’s kind of worked out really well so I’m pretty happy with how it’s turned out.”
McCarthy said his debut against the Titans, where he made 37 metres and nine tackles in 24 minutes off the bench, has given him a taste for more.
“Definitely, when I was up in Queensland [with Northern Pride] it wasn’t really a goal, it was just hopefully come out and enjoy my footy again,” he said.
“And this year it’s probably given me that taste of playing against guys in the NRL, the whole point in coming out here was to play at that level.
“I played well and had good feedback from the coaches so hopefully next year I’ll be able to kick on and add a few more games to those two that I got this year.”
McCarthy has won both the NSW Cup and Queensland Cup grand finals, after his success with the Northern Pride in 2014. He was also named in the 2016 Intrust Super Premiership NSW Team of the year.
“It’s good to have both Cups but it’s not really what I came out for, but I’ve made the most of the season,” the former Hull KR and Warrington back-rower said.
McCarthy knows he has to keep working hard to keep himself in the frame for NRL selection next year.
“I think I’ve hopefully shown them the capabilities of what I can do but I feel like I’ve got the ability to be in the first game,” the 28-year old said.
“It’s just up to me taking up opportunities when they do come but overall this year I’ve been real fortunate enough to involved with a successful reserve grade side.
“For Illawarra it;s their first premiership they’ve ever won so it’s kind of a big achievement for everyone involved in that.”