The 21-year-old has also been heavily involved in Ulster's rise to the top of the RaboDirect PRO12 table and their qualification for the Heineken Cup quarter-finals for a third year in-a-row.
Speaking ahead of his first RBS 6 Nations appearance, Jackson said: "It's probably the biggest game I've played in. I think I've come a long way since the Heineken Cup final (last year), so I don't think I'll be quite as nervous.
"I'm used to dealing with my nerves now, so I'm genuinely just getting excited."
Jackson had a disappointing outing in the 42-14 defeat to Leinster last May, but has undoubtedly learned from that experience and come back a stronger player.
Although Ruan Pienaar is Ulster's first choice goal-kicker at present, the Dungannon clubman is a very comfortable kicker in his own right - he boasts a near 75% kicking percentage from 35 shots in this season's PRO12.
In Europe this term, he accumulated 49 points (five conversions and 13 penalties) during the pool stages including a 21-point salvo on the opening night against Castres Olympique.
Asked if he thinks he has a point to prove at international level, Jackson admitted: "I would say slightly, yeah, but I'm not going to try to over think it too much.
"I want to play my game and I think with the experience outside, with Brian (O'Driscoll) and Rob (Kearney) there and obviously a great pack...I trust everyone around me and hopefully they trust me too."
Although the injury to Sexton has given Jackson the opportunity, he knows that it is a chance for him to begin the challenge for the out-half position held by the Leinster man.
"I kinda sat up a bit more in the seat when I say Johnny go down (injured against England) and then my friends all started shouting at me, but I honestly didn't (think), I'm going to be in now.
"I thought I would maybe come into camp and I'm back in camp and I'm glad it has come my way now.
"We are all competitive rugby players so I think everyone wants a starting jersey, so I know I'm young and coming through but eventually that is where I want to get to."
In an incredible period of 11 months, Jackson has gone from captaining the Ireland Under-20s, becoming first choice at Ulster and playing in a Heineken Cup final to lining out for an Ireland XV against Fiji in November (where he kicked five conversions and a penalty) to now starting a Six Nations clash.
"It has been an incredible," said Jackson, who needed to take some time after the Heineken Cup defeat to Leinster for his own development.
"I just forget about rugby for a while and took a break. Then I came back in in pre-season and there wasn't much else you can do except knuckle down and get used to new calls, new coach and the more games I've played the more comfortable I've felt with the team."
That development continued further when Ulster head coach Mark Anscombe bestowed the place-kicking duties on Jackson in the early stages of the season in Pienaar's absence. When the South African returned, Jackson says it was about training hard and waiting for his opportunity.
"I obviously kicked at the start of the season and i kind of felt it was a matter of keeping him (Pienaar) at bay for as long as possilbe. He is probably one of the best kickers in the world. He would probably have another 10/15 metres on me.
"I sat down with Mark (Anscombe) and he said he wanted Ruan to kick. There is not much you can do about that. I have just been going about it the same way I have, just training, training most days and whenever it comes, I'm still ready to go."
Commenting on the inclusion of Jackson for the Scotland game, Ireland head coach Declan Kidney said it was very difficult decision but added that that was the best compliment to pay the Ulster youngster.
"Paddy's inclusion was a challenge, giving the stature of someone like Ronan O'Gara there too. But when you try and take everything into account, the way everything's been going over the last couple of weeks I thought Paddy deserved a start in this one," he said.
Jackson played alongside Conor Murray at half-back in the 53-0 victory over Fiji and he feels that the experience will stand to both of them come Murrayfield.
"I think that will be a help. I felt very comfortable in the Fiji game with him. I thought we communicated well.
"It's only one game, but I've been training with him for the last couple of weeks so I think we are both ready for it."