parents disagreeing to me doing muay thai and acting on my own in general

26M. I am pretty sure this has been discussed across many threads here, but I will just post anyway.

I grew up under an overly protective, melodramatic mom and a control freak dad who thinks that martial arts is violence and does not count as exercise. According to him, the only way to lose weight is running, swimming and cardio exercises. Weight lifting and sports in general do not count as exercise but as hobbies. This is to give you the context of how they think.

Initially I never thought they would be this adamant that I shouldn’t pick up combat sports. So I innocently told my parent I wanna pick up muay thai and argued my way only to have my phone being withheld by my dad. (In my country, when you perform an online transaction an otp will be sent to your phone as part of 2FA after entering credit card details). I joined a gym (non muay thai, gym with weight machines and fitness classes) and realised that they had muay thai classes and went for muay thai. I really enjoyed it even though it was a watered-down version. I decided to try out an actual Muay Thai gym, as I got bored of the classes at the gym due to it being low in intensity, and signed up at a few gyms for trial. I really liked the class and the environment and felt that I should continue at least for fitness.

I am still an undergraduate student(I took a longer route to university as my country has conscription), and muay thai gyms in my city can be pricey but often have discounted prices for students. So I thought of it and I broke it to my parents that I wanna pick up muay thai for fitness. Especially since I am obese, I enjoy muay thai lessons more than gym and that I struggled greatly with keeping to a strict diet. I even shared with them the benefits such as the workout being a good HIIT, being good for building functional fitness, being an good workout and the environment is friendly and accommadating for beginners. Still, these were what my parents felt that the gym convinced me and not something that is proven by research.

At this rate I really dont feel like continuing and just wanting to give up and pursue when I start working. It is gonna be difficult but after seeing several working adults picking up muay thai to improve their fitness I feel like is not something impossible.