Wash your hands a LOT (before and after every patient contact, before and after lunch, eating, etc.) and avoid touching your nose/mouth when at work. Get a sign made for sign-in that tells all patients with cough/sneeze, etc. to cough into their sleeve. Use a paper towel to touch door knobs, etc. Have some cleaning wipes to wipe down keyboards, phones, etc. at start of day. Think about things sick patients or other personnel who don't wash hands touch, and use hand gel after touching them (shared thermometer, scale, clipboard, etc.) Use 1-2 pens that you wipe down and that never leave in your pocket, not ones used by others. Eat a healthy diet.
May be happening because you are in a smaller space (exam room with closed door, less air flow) compared to larger patient room. In hospital, you had probably 4-5 patients per shift. If exposed to 20-25 people per day. of whom 16 have an infection, odds are against you unless you have a huge awareness of what spreads them, what surfaces, objects, etc. are likeliest sources, how to reduce # of pathogens that make it into your body.
Here is an example: If you use hand gel, and then open door room, you may as well not have bothered. Instead, open door, leave it open a few inches, stick you head in and say "Mr. ___, I'll be with you in a minute." then clean hands and enter the room.
Get your employer to put wall mounted gel dispensers outside of very room, or have a bottle in every single room, including your charting areas. Get someone assigned to wipe down on buttons, computer keyboards, door touchpads, shared equipment, etc. every day with disinfectant. Make the case that they will recover the cost if it means that each employee is sick two less days per year. (AND I am sure there is an OSHA rule requiring this that they may be breaking.)
Good luck with this.