Hello, I Think I May Have Heart Palpitations. I Have

Hello, I think I may have heart palpitations. I have been smoking recently, it was about 1-5 a day for a while but I quit when I noticed my heart was beating fast randomly when I was just sitting and doing nothing. I believe it is a palpitation because when I get chest discomfort I can help by leaning forward or changing positions. I have felt a fluttering feeling once as well, and a sort of trembling feeling before. Recently I have not been eating the best as well, I've been eating a lot of sugar. The fast heart rate hasn't happened recently but I get chest discomfort.