Why do I feel sick?

I often feel nauseous and I feel like a night throw up around 2 times a week (most of the time in the evening) sometimes I do throw up my mom thinks it's acid and I agree but this has been happening for years but it has gotten worse in the past two years. Specifically I feel like there is a lump in my throat which is the feeling that everybody has before they throw up but I never have diarrhea or anything else it's only this, so what is the problem and how do I fix it

O ya I forgot to say sometimes I will take a tums or a roll aid and it will help and I burp a few times