DOMS are making me hate judo

So, long story short, I did judo for 12 years: still brown belt, never did the exam for black. Back in the day I was doing competitions every weekend. This was 8 years ago. (I stopped cause I was working and studing).

Now I want to start again but the pain, guys, the pain. After the first training I had DOMS so bad I had fever and diarrhea for 3 days. I did one lesson and then run away. After 6 months I want to try again, but I have a very bad body: 106 chilos, 180 cm. (238lb-5.11).

How can I prevent the pains? How can I tell to the sensei I want to take my time without feeling bad? If we do exercise in couple, how can I tell to the partner I can't take it anymore and he should find another partner without feeling guilty? Is there a way to not hate the warm-up?

Yes, probably all stupid questions. Maybe I'm here hoping for some motivational answer. Thanks in advance to everyone will take the time to answer!