Advice please

Just wondered if anyone knew what i could do for my babys blocked nose. He is struggling to sleep for long because it blocks up too much. Ive been giving him saline drops but it isnt helping much. Sometimes he struggles to have his bottle because he can't breathe through his nose. But he has been quite congested since birth (he is almost 7 weeks old), sometimes it gets better but it has never cleared up. Any advice would be great !