He loves me, he loves me not?

So, I'm off to Cornwall in the early hours of tomorrow morning which is utterly exciting! :)
I'm so glad that the time has finally come, I've been in need of a break so bad.
You see, my boyfriend has been in Portugal for 2 weeks, and now he's a different person.
I don't even know if I'm with him anymore, to be honest. He's met a French girl out there and they seem to be spending all the time they can together.
He's humiliated me beyond belief, because he's gone on a family holiday so all his family know what he's been up to. So when I go and see him when he comes home, they will all be sitting there looking at me thinking, 'I know what he's been doing'.
When he actually does bother to contact me all he talks about is this girl.
And yes, I am jealous. She is beautiful and thin, and I'm not particularly great looking and I have big wobbly thighs.
He's been watching her prance round in her bikini looking amazing, how is that supposed to make me feel?
I told him that I'm jealous of her and his response was, 'So I guess that means I can't go and visit her in France then?'
NO YOU CAN'T! What sort of a question is that?!
Next week me and my boyfriend would have been together for 3 years and we was going great until he went away. Now everything's changed and I don't even know where I am with him.
We know each others passwords for everything because we trust each other, and last night he changed his Facebook password. Now, for us this is a big deal. Usually, we wouldn't even think about doing such a thing, so what has he got to hide?
So, this made me change his password back, and he's changed the password again. So, I changed it back and then he changed it AGAIN. So I changed it back. He will probably change it again while I'm away in Cornwall.
I don't know what he's playing at but it's quite clear he doesn't want me finding something out, and perhaps doesn't want to be with me anymore. I know I mentioned it earlier, but we was perfect together. Absolutely perfect. I don't understand how it could go so wrong.
He needs to sort his priorities out.
I've been in a right state, I thought I would have to call the ambulance last night as my heart was pounding and racing, my breathing was difficult, I was dizzy and shaking.

I really don't know what to do, I'm not coping very well.
This trip to Cornwall will hopefully do me good and take my mind off things.

I don't know if I should ignore his calls and texts when he gets home from Portugal, or if this could make things worse. He might think, 'She doesn't want to know me anymore so I can find someone else'.
I want my boyfriend back, I don't know whats happened to him :(