SO much is dependent on where your lesions are. My husband had a personality change in his 20s. He suddenly had issues with depression and anxiety. We think that's when the lesions started appearing, but it was 20 years later he was diagnosed with MS. He also has memory issues, and conversational brain farts. It's scary.
Worrying about mental illness is not going to help you...seeing your doc and talking about your feelings will. Maybe an antidepressant can help-even if this isn't depression. Provigil and effexor have really helped my husband stay focused. I'd also recommend diet changes, like jimmylegs suggests. Omega 3 (fish and flax oils) REALLY help the frontal lobe of the brain. Trans and saturated fats can really mess with your mind. My husband has benefitted from diet and meds.
And since you posted this in mental and SPIRITUAL health, I'll offer my 2 cents...keep connected in your spiritual life. Meditation and prayer really help, however you find ways to express that. Yoga helps me center and my husband prays and uses music to calm his soul and mind.
hang in there, and keep talking...
Husband dx RRMS 3/07
dx dual jugular vein stenosis (CCSVI) 4/09
dual stents placed 5/09
CCSVI in MS