I have been on a diet and feeling something nasty in my throat?

[Ilovelipstickx]

I thought I need cut down and lose weight because I have been eating so many sweet things I like and wanted do something about it to change my weight. anyways I been exercising in the bike and played all the song album still it stopped so i got off the bike and feel tired and sweaty over that. Every time I get this horrible feeling i'm going be sick when really i'm not it's just makes me feel like i don't want eat anything when i need eat something it comes up in my throat really tight like i feel like i want to let it out. at lunch time i felt like that and it was horrible...I'm going have Gaviscon that would help. at morning i wake up feeling it again and it it annoying so i had cereal and i didn't feel uncomfortable eating it so the stuff in my throat made it worse i went to the toilet to be sick but nothing comes out is it because i eaten less and my body not use to it? I haven't had that before when i was eating lots junk food it happens when i was in diet has anyone got advice on they know what this feeling like being sick and it's in your throat when you don't eat much anymore?
Sorry i mean i didn't feel comfurtable eating it when it feels like something want let out in my throat..