I will see the gp,
No lump that I can feel, swelling as in boob feels a bit bigger than normal.
I do wonder if its all hormonal but the dizziness thing has scared me a bit. Again hormones make me more anxious.
I went to the GP last year full of anxiety that one breast was bigger than the other. Like you, no lump. He had a good look and feel and said they were slightly different sizes but that is normal, we are not symmetrical. Could it perhaps have always been like this and you have only just noticed?
For example, mine changed after breastfeeding and the one I thought was bigger was just actually flabbier and was the one that had gone as flat as a pancake when I stopped breastfeeding. It may be something you have only just noticed but has always been like that, or you haven't put weight/ muscle on evenly which also happens particularly if the right is your dominant side. However, I agree with Jules you should get it checked, not least because you need to calm your anxiety down. Talk to the GP about that as well as your breast.
Oh and with sore breasts, caffeine makes it worse for me so perhaps try laying off that for a few days!