What to do from now until IB SA offer?

(I recently saw a topic similar to this for S&T but I wanted to ask this for IB specifically)

A bit of background on me: I spent most of the last 8 months, like most people, grinding and working very hard to secure a lower-tier BB offer. WSO was extremely pivotal in helping me get an offer so I want to thank all of you for your advice and suggestions. That being said, since recruiting has ended I have found myself feeling a bit guilty. All through the recruiting cycle, I was always either networking, prepping for technicals or keeping up with industry trends. Even with my grades and health, I was very motivated in all aspects of my life. After getting my offer, I have found myself not being as motivated to prep for my SA position next summer. Apart from my regular classes, I am also working a part-time IB internship at an M&A boutique bank during this semester. The experience has been really informative, as it is my first IB experience, but I have not gotten to do any modeling or anything else technical for that matter.

I know I should try my best to relax and enjoy life for the next few months but I am feeling guilty that I'm not doing all I can to ensure I get a return offer after the summer. Additionally, the high of getting an offer has caused me to care less about my grades (I go to a target and I am seeing this trend in multiple friends with IB SA offers as well). A bit off-topic, but I had been really into working out during the recruiting process and I have even found myself losing motivation for that as well. This concerns me because I know that during the summer we barely have any time to exercise, so I want to get into the best shape I can before then. I have had friends tell me to take modeling courses or even Excel classes over winter break, but I am still lost as to what to do. Do any FT Analysts who have recently been in my situation have any advice? Is this a normal thing for most kids with SA offers? Thank you in advance for your suggestions.