Nearly 8 month old stopped feeding

[Liviam]

Well up until the last week my nearly 8 month old DS has been an absolutle tropper feeding - so much so I thought he was permamently attached to my breast and feeding for about 10 minutes in total. In the past week his feeding has done a full 180. I am having a nightmare of a time feeding. I can get him to go to the breast but he is only having a few sucks - I'm lucky if I can keep him in my lap, attaching on and off for 5 minutes. He is having three solid meals a day. Since he has been fussy I've decreased his solids and giving him solids about 1/2 hour after a b/f so he isn't full at b/f time. I am offering him the breast and if he isn't interested he is biting me. I've even expressed and offered it to him in a bottle (he has the occassional bottle) only to get the same reaction.
He is pooing every day, sometimes every second but his urine output is really down. I am changing him every 4 or so hours and I'm having to pull nappies apart to find any wee and they are smelling really concentrated. He also has a running nose too.
It has been a big developmental week for him. He has learnt how to crawl and he is/has cut 6 teeth and is extremely interested in everything going on around him so I'm feeding in the least stimulating environment I can but it doesn't seem to help.
We do the sleep - feed - play routine so he gets offered the breast when he wakes. I feed him straight away overnight but I've been waiting 1/2 during the day to work up an appetitate. He is feeding about 4 - 5 hourly during the day. I can get him to have a few sucks before sleep. AAARRRGGGHHH it's all messed up!
I hope that makes sense. I don't know what else to do. What can I do to get him back to feeding normally or is this his new normal? Or is he weaning? I really hope he isn't weaning!! I also don't have AF back yet but I do have a mirena in.
Many thanks,
Dan.

P.S. I'm wearing pink knickers today cause that seemed to be the only thing I left out, LOL!