what’s wrong with me .. i’m scared 😕😰

im 23 years old. and i read that when ur older you get heart disease not when ur young but lately my heart rate has been alittle high .. Idk why... I’m not doing anything wrong. When i work out i feel better but i feel like it’s beating fast or sowmthing.. In the night i feel it beating a bit fast .. I do have anxeity but i don’t think that has to do with it.. idk why i was taking this magnesium tablet but stopped because i thought it was triggering it.. Im kinda scared. should i see a doctor if it gets worse? i just want to have a normal heart rate. 😞 im a nervous person tho so and my mom said i can’t have heart disease . i am stresssed alittle but when i stress my back hurts and shoulders and neck.