I've been having strange stomach problems. What should I do?

I am a 15 year old female. I take Vyvanse/Adderall occasionally due to my ADHD, occasionally because though my parents get my prescription/medication/and the such, they do not let me take it very often because they believe I am "cheating" the system. rolleyes sucks to be me, but whatever.

For the past month and a half, I have been having strange stomach problems. At first, it was just occasional pain/discomfort.

In the second week, I had a severe bout of pain, and I couldn't even walk. It was a sharp, pulsating pain in my lower left quadrant, and less but still pulsating pain throughout my lower quadrants. 

In the third week, it levelled out. I had vague pain/discomfort daily in my lower quadrants, but I chalked it up to bloating or gas. I had normal BMs every day. 

In the fourth week, it started to get worse. My lower quadrants began to hurt like a slow burn, and my BMs started to increase, to at least 5 a day. I was having mostly solid BMs, and a couple bouts of minor diarrhea. I did notice that my solid BMs were slightly skinnier in width than normal. 

In the 5th and 6th week, it began to get chaotic. My entire stomach started hurting a lot more than it did earlier, and a sharp pain that began in my lower quadrants shifted near my diaphragm area. My lower quadrants remained in pain. My BM count went up to 10 times a day. I had diarrhea, skinnier stools, constipation, and translucent, white-ish clumps that kind of looked like if you scaled up a macrophage. (I assumed that was mucus.) I was very nauseous, and woke up in the middle of the night to throw up. I started getting fevers of 99-100F at night. 

Separately, I've started gaining small sores on my arms and legs. At first they start as bumps, but then they open and drip a clear liquid. I only have about 6, but they've started since the 5th/6th week, and they are itchy and won't heal. Was wondering if these were related?

It is now the 7th week. I currently taking Pepto-Bismol, Probiotics, Peptids, Tums, and Vitamin D. However, I still have a sort of burning discomfort in my entire stomach, and my BMs are down to maybe 3-4 a day. However, my stools are a little skinnier than usual, or diarrhea, or darker than before this whole pain occurred. Additionally, I get hit by the occasional wave of nausea.

I would've ignored it, but there is a history of GI-related cancer in my family, and idk how cancer manifests so yea.

Any ideas/suggestions to remedy this?

First off, I'm glad your parents don't give you those drugs on a regular basis. Vyvanse comes with a black box label warning, and both are highly addictive.

Have you taken or used anything else?

Think back to before your symptoms started, and when they started. If you honestly did, or even if you didnt, you need to see a specialist. An endocrinologist . I have heard taking probiotics isn't for everyone and can have adverse effects if you dont need them. But only with ct scan, mri, maybe a colonoscopy can a Dr tell what is going on in your stomach, or liver or colon. I don't think you have cancer. But if you were healthy 6 weeks ago, think back on what you ingested, or what you were around.

The itchy bumps may not be related, but your liver could have something to do with it. I ha that, but also had a skin cat care removed and it cleared up. Also ha my gall bladder removed. But the gall bladder does malfunction on its own. It is housed up in under your liver. Mine was full of bile and nobody addressed what causes that. It had to come out tho, because it was badly swollen. You really have to eat clean and take care of your body. Because there's a saying: "when you wear your body out, where you gonna live?"