First of all, you should try your level best to reach to a doctor as soon as possible after getting bitten by a brown recluse because making it late can cause you severe damage and even the venom of brown recluse can take your life.
However, if you are far away from the hospital then you have to rely on self medication. You should immediately apply a medicated numbing spray on the affected area to control the discomfort.
You can use Solarcaine which is pretty effective in reducing the pain and discomfort that you feel after getting bitten by a deadly brown recluse.
Usually, when brown recluse bits a human, it causes swelling on the affected area. This swelling increases as time passes and you have to stop it. Take an ice pack and apply it on the affected area for stopping the swelling. Applying an ice pack will reduce the temperature of the affected area and will help in stopping the swelling.
However, you should understand that it is a temporary treatment to stop aggravation of swelling and discomfort for a limited period of time. Do these things in order to find enough time to go to hospital or to a doctor for getting proper treatment.
You should also take antihistamines for avoiding any allergic reaction. However, make sure you do not exceed the recommended dosage as it can cause you more trouble.
If the brown recluse has bitten you on your torso or face then you should rush to the hospital because the necrotic venom can cause you severe harm in these areas more rapidly as compared to other areas of your body.