I recently decided to grow up and start cooking for myself, but after a couple of bouts of food poisoning in the past from fast food I am deathly afraid of eating undercooked meat. I just cooked a burger and the meat thermometer read 155 (medium well…) but the burger was clearly not completely cooked in all areas, despite the outside being almost completely burnt.
Cooking on the stove in a frying pan with temp set to 7.5/10.
When I fry ground beef, I do it on a very low temperature, squeezing the patty with a spatula to see if blood runs out. Upon suspecting it to be done, I squeeze it with the spatula again between paper towels to observe if I get just oil or blood.
Repeat as needed. 
Get a George Foreman Grill. This and a crock pot are great boons to mankind. The grill is great for burgers, chops, boneless chicken…
Your oven is set too high.
I HATE those! One had a Nasty Accident and fell off the counter (honest!)
The replacement was too small, too sloped, had no off switch and to short a power cord.