I just felt piti for the first time. How can I transition into the first Jhana?

This morning after being woken up by a motor (Lawn mower? Motor Bike? It was quite brief) I decided to do a meditation. Focussing on the sensation of the breath on the tip of my nose, I was more successful then it has been in a few years, and after 30 minutes or so I reached access concentration. I have had phases were I would consistently reach access concentration before, and had reached it a few times in the last week, but due to life stress it has been several months to be honest since being able to do so consistently.

After feeling my concentration deepen for another 20 minutes I started reaching/feeling piti. Unfortunately, I couldn’t maintain equanimity, it felt like the happiness and pleasure/euphoria was bubbling inside me and I couldn’t remain consistent in my breathing. It felt like I almost had to gasp for breath and I was struggling to stabalise my breathing and remain calm and undistracted.

After a few minutes the piti steadily subsided. While concentration remained, and I meditated for another 20/25 minutes, piti didn't emerage again.

Overall I was very pleased with the session. I have ADHD and for a while I have been starting to doubt whether I could ever achieve a jhana, because I have been getting into Access Concentration inconsistently for over 5 years, but only brushed piti perhaps 5 times until now. I think in the past I've tried to 'capture' it, and that has always ended in failure.

This time I just had a smile and piti arose very naturally, but I honestly tried to continue to focus on the breath as it grew and grew. I likely became too excited and started to anticipate it, and thats when I lost control, but Leigh Brasington has said at some stage your focus should switch from a physical sensation to the feeling of pleasure, so I am feeling a little ignorant on how to ride out the transition.

The last 20 minutes were interesting. I had a nice relaxed focus on my breathing, and I was still pleased because it was certainly the best session that I've had in years, but I wasn't sure how to encourage piti to arise again. My smile had slipped at some stage, and I put it back on, and perhaps I brushed piti again, but it didn't grow and was nothing like before.

I enjoyed the rest of my session, but I felt like my concentration was no longer deepening. It was a nice and relaxed focus so I kept it up for a while, but eventually I ended it and decided to write this, half so I can remember the sensations and also so I can get help on how to progress.

Cheers!