What causes bruises and bumps on arms and legs?

Hello doctor,

I am an 18-year-old male with 5 feet and 9 inches in height. I am not sure what to say but, I have had these strange bruises appearing on my hands, more than one and some are tender while others are not. I also have these bumps throughout my arms and leg. I think there are some around my torso area. I am inclined to say the bumps are maybe swollen lymph nodes, they hurt when I am active and the pain gets excruciating. But after some time in bed, the pain goes away. Also, I tend to sleep a lot. so much that it is noticeable, and whenever I sleep eight out of 10 times I wake up drenched in sweat. Even though my room is very cool. I met with doctors a few times and they all came to different conclusions. The first doctor I saw said these were bug bites but my bed is relatively bug-free and even after I changed the sheet bumps still appeared. The second one said that I have swollen lymph nodes and that I will just have to let them run their course to go away. The third doctor said I have the kissing disease, but besides the bumps or swollen lymph nodes, I had no other symptoms of mono disease. She told me to take over-the-counter inflammatory drugs to reduce the bump size. I took them and it worked for a month or two. Almost all if not some bumps disappeared. But eventually, they all came back. All the doctors were clueless about the bruises on my hands. They just asked to keep an eye on it and I have, more and more bumps infrequently. Kindly suggest.