It is good to be concerned about medications while you are breastfeeding, as you are obviously at risk for passing these on to your baby. Given the fact that your symptoms are bothering you to such a large degree, you should consider speaking with either an allergist or an ear-nose-and throat surgeon
) to discuss other medications that might be more appropriate to control these horrible allergies you are describing.
In general, when people have severe allergies, the first line treatment is an intranasal steroid. These are absorbed locally, and only a very small amount actually is passed into your blood stream (with some slight variation based on the type or brand of steroid that you choose). These offer excellent improvement of symptoms, and might be a good choice for you and the symptoms you are describing. Even more gentle would be the addition of nasal saline irrigation, which can be done regularly throughout the day and has been proven to help by flushing out some of the allergens that are inside your nose making you miserable.
As for the other anti-histamines that you describe, there is only limited research with regards to their use in breast feeding. While some of them are not likely to be harmful in small doses, please speak with your doctor
about the best options for you.