The 27-year-old missed the vast majority of Ireland's RBS 6 Nations campaign after being forced off with a hamstring strain 20 minutes into their second clash of the competition against England.
A foot injury soon followed, ruling him out of the final game in Italy, and having spent almost two months kicking his heels, Sexton feels strangely fresh ahead of what will be a busy summer for him as he battles for the Lions No.10 jersey.
And with a European Challenge Cup and Pro12 final still to play for Leinster, the club he will leave for Racing Metro next season, Sexton hopes to rediscover his form in all facets of his game just at the right time.
"There's a lot going on in my head right now. We've got a big end to the season with Leinster and then we're straight into the Lions which is the pinnacle of your career," Sexton told the Irish Times.
"Then there's the move to France which was a big decision for me after nine years with my home province, but the most important thing is finishing on a high with Leinster.
"Hopefully I've used up all my injuries for the year. It feels strange to feel so fresh at this stage of the season, usually I'm knackered. I've only played four games after two months off so I feel great.
"I'm starting to get a bit of match fitness and, hopefully, my match sharpness back and I hope I peak at the right time with these two finals for Leinster coming up."