I Think There Might Be Something Wrong With Me, Need Some Advice, Please?

Ok, I am a 17 year old male around 6″4′ and about 230 pounds and for the past couple of days i have noticed my heart rate has been through the roof. I get dizzy and lightheaded very easily also while getting up or walking up my stairs. I have also not been able to eat much of anything the past couple of days because when i have food in my mouth it makes me feel sick to my stomach and to swallow food makes me fell like im going to throw up. I have too noticed a very sharp almost squeezing pain right below my ribcage more on the right side of my stomach whenever i am walking or anything. I drink 1 to 2 large cups of coffee in the morning and have for some time now and also smoke but have gotten down to around 8 ciggarettes a day. I have suffered from chronic insomnia since last september abd since have been taking Tylenol-pm to help this and take 4 (or more but not more than 8) pills at night to go to sleep and if i try sleeping without it i cannot fall asleep and if i do then i wake up 3 hours later and i toos and turn in my sleep the whole time, so its not possible for me to get off Tylenol pm. I also sometimes consume energy drinks or energy shots throughout the day (Rockstar, Monster, NOS, 5-hour energy shots, 6-hour energy shots, and also i have tried Redline recently). I know that no one can diagnose me through a computer but if you can give me any idea as to what these symptoms could point too then i will greatly appreciate it.

ps: In my past i have expirimented with many illegal and prescription drugs. I have abused every kind of opiate painkiller other than Fentanyl. I have abused every kind of illegal street drugs out there other than heroin (although have had ecstasy laced with a small amount of heroin). I have also abused every over-the-counter drug that can be abused. I have not touched any kind of drug other than my Tylenol-PM and Percocet (prescribed for a tweaked neck with massive neck pain) in a long, long time though.
Also i have clinical depression and it usually doesn’t cause me much problems when im out and around friends but the past couple days i have even become depressed while with friends. I also get panic attacks but only a couple a month and i have no insurance out here in Nevada but can go to the emergency room if its necessary (There are no Kaiser Permenentae hospitals in Western Nevada, but Kaiser will cover emergency room visits)
Its funny that you talk about Ritalin seeing as i abused it a lot in school, doses up to around 150+ mg’s at a time