Infected deep cut - How to treat?

Just because it's red and itchy doesnt mean its infected. Itching is a sign of healing. If you're running a fever, your body is fighting an infection. At that point you will need antibiotics. If you can not seek professional help place antibiotic cream on the cut as much as possible. Keep it clean as well. I'm not sure about your area but a lot of large chain pharmacies and super stores have clinics in them that could address your cut for less than fifty dollars.