can you really blame him though?

Sounds like a perfect way for you to get him our of the house... just put w bunch of spiders in his room and tell him to get an apartment lol

Once I saw a big black spider run underneath the cushions on my couch. I gave away the couch that very day. I knew I could not relax if I sat on it again.

I'm 31 and would do the same thing, so yeah.... I can't even look at photos or videos of them. Which I know is really stupid when I think about it later, but I see them and my body just goes into a panic mode I can't control.

That's a fine reason

Why mention his age, do you think mental illnesses only occur in children and magically evaporate at adulthood's onset? I had an extreme phobia for years & did a lot of reading. A phobia's a "pressure relief valve" to vent anxieties the person is unable to vent in the proper way. One case study involved iirc a cartographer or some other early European explorer of North America, who had a terror of honey. Since he refused to show fear at work he bottled it up and it had to come out somewhere. My own phobia was likely due to verbally abusive parents. Being unable to fight back or leave, as a minor, I had to repress my misery, and it came out as phobic attacks. So (assuming you aren't the problem, OP) if you want him to improve, help him face whatever's making him stressed. After addressing the underlying cause, the phobia will likely remain, due to, well, habit is too condescending a term. It's kind of like how a musician's hands can play a well rehearsed song without their mind engaged- repetition trains the body to follow a certain procedure. So the second part of getting cured is retraining his body to not gush adrenaline upon seeing a spider. Exposure therapy is what worked for me but I beg you, do not try some harebrained version of it! Locking a claustrophobe in a coffin overnight is NOT exposure therapy, nor is dumping spiders onto an arachnophobe or throwing someone in a lake who has a terror of drowning. That shit just worsens the phobia, maybe adds PTSD. Proper exposure therapy is done in a safe, supportive environment, with the phobic in control of how far they push their limits. It should never be scary. In my case, due to difficulty finding a useful shrink, I got desensitized with a non-shrink. A geek in love with the thing I feared. His enthusiasm for the topic helped create a positive energy for the sessions that a shrink just could not have offered. It was great. Six weekly sessions of one hour was all it took! I wish I'd done it sooner!