Anep, be very careful to protect your ears each time you're in a loud jamming session.
Tinnitus is just the beginning. Frequent exposure like this will lead to noise-induced deafness. One of my friends, not yet 40, already has NID in one of her ears due to noise when playing in a loud band for a number of years in her younger days. I've also seen a number of young people started having NID - not so much due to band but loud working conditions.
Earplugs are definitely indispensable, as suggested by fored. For a musician, losing hearing is almost like losing your future in music...