Feeling sick...

How to ruin a perfectly splendid day. I hate myself right now.
Clare came over for what was supposed to be a chat and a stroll over to Crooks Peak, followed by a bit of dinner. Everything was ok up to a point, but she started on to me about how John has basically slept his way around work, and taken drugs, and a whole host of other very nasty things about him and I just jumped onto the bandwagon.
The more of John I learn about the more I dislike him. Obviously Clare is going to be just another notch on the bedpost and I hate to see how she is totally blinded by "how nice he is". But it doesn't excuse the blasting I gave him - not in front of Clare anyway.
Clare told me today that she wished that we could be together again but that we couldn't have carried on the way we were and it's only through splitting up that we have both seen how we went wrong in the first place. I'm afraid that this news got the better of me. For a second I imagined us being back together and it was so wonderful that she was hoping that we were heading that way that I just resorted to basic and ignorant instincts. I tried to kill off John in her head and just kept going on about him, trying to make her see what he is really like even though I know that she is fully aware of it already and my emphasising it doesn't help.

I can't even write this just now. I feel like I have eaten bad fruit. My whole stomach is churning round and round and I am so angry with myself I could scream. My feelings for Clare are so strong that the slightest thought of us getting together in the future (however far in the future it may be) just set me off and I came out with ridiculous statements and attacks on other people that I really shouldn't have said. I have just undone all the good things we had going for us, and now she thinks I am just trying to break her and John up, which isn't true in that way. Sure, I know he is wrong for her and she needs to be alone and not with anyone, even me, but I don't want to wade in and cause trouble. I am supposed to be helping Clare, and today I just undid all the hard work I have been putting in to try and help her come to terms with things. I've even managed to make myself feel bad.
I even made a parting piss-take about John being on drugs as she was driving away.
I am so disappointed with myself. I have just sat here and cried for 15 minutes in total devastation about letting Clare down, and also myself. I feel as low now as I did a few weeks back.

It happened because I was having such a good time, and I forgot myself. It seems so natural for me to be with Clare, having a laugh and a joke, taking the piss out of things, and just being free to enjoy life. But I lost the point that she is 'involved' with someone else and despite where this is going and how bad he is for her, it's all her choice.
I have been looking forward to this for so long, and when she came round I screwed up big time.