My nose bleeds from the right nostril whenever I blow my nose in the shower, it's been weeks of this?

Epistaxis. You may have developed an exposed vessel on the nasal septum or caused an abrasion that isn't healing. Blowing your nose in the moist environment is the right way to clean your nose... You may need cautery of the area... Very simply done in an ent's office.
Hmmm. This is where the history is very important. Do you have allergies? Do you snort drugs? Do you put things in your nose (such as rolled tissue paper) to cleanse it? If a tear in the nasal mucous membranes occurs for any reason, it heals by making a clot that contracts after 24 hrs, and pulls the edges of the wound together. This causes rebleeding usually in moist warm setting like a shower.

Related Questions

Catch 22. Got lots of nasal drip from a cold but every time I blow my nose (even softly) a nostril scab tears& my nose bleeds. To blow or not to blow?

This blows. Stop blowing and let your nose heal. When it stops bleeding then you can go back to trying gently blowing it. Consider an over the counter medicine like Sudafed to help with the stuffy nose in the meantime. Read more...
Lubricate. Use a dab of vaseline or Aquaphor or KY jelly twice a day inside your nose. You can use Afrin [the generic oxymetazoline is same] for a few days, not more than a few. You can also snuff some water [usually salted water] up your nose and suck it in to clear out mucous. Read more...