Injured knee during martial arts training 1 week ago

Patient: Hi, So I had a knee injury a last week and I had a few questions about it. I injured the knee in a martial arts competition, it was kick from the outside and buckled in and immediately gave out. I saw a doctor the next day, she told me it was probably a sprain of the MCL ligament. She prescribed RICE for a few days, and said it didn’t seem that serious and I would probably feel a lot better in just a few days. It’s been one week and while I feel slightly better, I don’t honestly see much improvement in functionality. I can stand on it now without pain and can straighten it all the way so it’s a bit more stable, but there’s still range-of-motion issues – I still can’t bend it past 90 degrees, I can’t twist it at all, and my medial quad muscle is functionally inhibited – when I try to flex it from a straight-legged position it is soft and spongy. It’s also still quite tender at the site of the injury and painful to the touch. So I’m wondering what’s next – should I return for a follow up exam? Do I need phys. therapy? Surgery? Or should I just give it more time? If so, how much time? Finally, I have a vacation coming up in 3 weeks with several scuba diving trips planned, and I really need to know if this will be safe for me to do before I spend more money on the trip. Hope somebody can help, Thanks!