What would a big white mass be in a MRI of a left knee COR T1 Pre? Knee pain

[RaiNyZzZ]

I've hit my knee a month ago. My doctor suspects of a torn cartilage or previous injury and request an MRI. There's a pretty significant white mass in between the joint (Between the bones), I have no idea what it is, but it is where the little black meniscus triangle on the left side should be (like a bone?).I feel like sometimes my knee might give in, sharp pain with movement, pain when stretching and knee sore to touch (top left, below knee cap, lower right side). My follow-up to review the results of MRI is in 4 weeks and I'm in a lot of pain... besides P.R.I.C.E. is there anything I should avoid or do to help cope with my pain? I can share my MRI images if needed... thanks!