After doing a lot of take downs in training my neck gets sore too, from me tucking my chin when going down so I don't hit my head on the floor. I know mine is because I still don't have the muscles build up in my neck to do one take down after another for an hour and a half. However, what baffles me is that yours got worse after a massage as a massage relaxes and soothes the muscles and should have helped. So I am wondering if you maybe got an injury rather than just weak muscles. It doesn't sound right and I think I would go see a doctor if I was you. Neck injuries are nothing to mess around with.

It happens, I call it gi burn. (As opposed to mat burn)

I have soooo been there.

Whoever it was seems to be applying alot of leverage on the collar grip,causing friction between the collar and your neck. Pharmacies can give you a lotion that will reduce the pain. When you wake up do some neck stretches to loosen it up a bit. Roll your head up,down and around. It shouldn't happen often,if it does then your partner should be made aware that it's harming you. Sometimes in randori things get a little rough,but it shouldn't be a regular occurrence. It was your first session so expect one or two bruises/aches. Keep it up.

Train hard,fight harder,live better.

Ice it for no more than 10 minutes twice a day for a few days and don't aggravate it with massaging if it made it worse. If you feel any numbness or tingling in your fingers or toes then go to a doctor for an x ray. When it gets better, ask you coach/sensei for exercises for your neck to keep that from happening.

I suggest that judo may not be the martial art for you. Go for a more leaner martial art, like Tai Chi.

Yesterday my friend took me to a Judo session and today my neck has been killing me and is achey I know my body's not used to it and I was warned but my mum gave me a neck massage and it got worse any suggestions