Would U Help Me? I Have Had Sollwen Knee For

Would u help me? I have had sollwen knee for the past 3weeks on and off. The other night i was feeling my knee and i find a lump what moves whitch it is only on the left side of my knee and it become alot sore and sollwen and i have been trying to get in to see my gp for a bit of time they say they are full booked in.