I Have Experienced Many Losses Over Just The Past Year

I have experienced many losses over just the past year (Friends, Great Aunt, dog, ect.) and have been enduring excessive periods of stress, anxiety, and more. Over this time i have been noticing a feeling of jellowness in my legs, a ton of nausea, and this feeling of hollowness in my chest. I have read that lots of stress can lead to many different heart problems. Im obviously not a trained professional, but i hav been very curious. Also did i mention im only 14 and in 8th grade?