Can I win in court suing for birth damage of my son without a lawyer?

My son was horibly damaged at birth due to errors by both doctor and the hospital. His blood oxygen was 17 percent ( below 80 percent is brain damage). Yet noone told us till i read the medical record years later. He is a slow learner and has problems in school. I went to lawyers in the past and all wanted a slam dunk case. "If he doesn't have cerebral palsy I won't look at it" types of replies. He's 14 now and times running out. I won 2 small cases without legal representation in the past ( both parties settled before we got to court) but I am not a legal expert and fear the lawyers will simply stall and game play. I woke up to see my babies fetal heart monitor on 47 beats a minute ( 120 to 160 is normal) , I ran out to tell the nurse who WAS ASLEEP AT HER MONITOR . The doctor ruptured membranes causing prolapsed chord for no medical reason, etc. HOw do I start a law suit to help my child later in life without a lawyer? Can I win it without one? The doctor refused to do an ultrasound