Continues Cold

Hi I have a continues cold for the past 6 to 8 months or even more, I went to the pharmacy and purchase an inhaler that clears my nose and allows breathing properly, but this lasts for only a few hours and then I gotta use it again.

I have not been taking any specific medication for the cold and just using the inhaler. Sometimes at night I find it difficult to breath and feel that there is a heavy congestion in my lungs.

Since its been lasting for so long now, I am tending to get worried.

Can you help me and let me know what the problem is and if its serious.

Thanks,