Need some advice: Should I raise my dose of Adderall? (long)

Here's the story:

I currently take 30 mg of Lexapro 1x per day (for OCD) and 10 mg of Adderall IR 2x per day for a total of 20 mg in one day. My Lexapro dose is optimal for my OCD.

I take the Adderall to counteract the following side effects of Lexapro:

-Lack of motivation induced by long term usage of an SSRI

-Horrible sexual side effects of Lexapro (my wife is losing her patience with this)

-The SSRI side effect of diminshed concentration and attention span

All of the above side effects are caused by Lexapro's potent boosting of serotonin in the brain; this in turn decreases dopamine in the frontal cortex.

My focus has gradually improved on the Adderall at the current dosage.

However, I feel like I have built up a tolerance to the following Adderall effects. After taking it for 4 months, the Adderall doesn't work nearly as well as it used to for the following:

-Increased motivation (an effect I love; It's amazing how much I can get done; My work performance has sky-rocketed)

-Increased sexual desire (losing this effect really bothers me)

-Increased confidence (While on Adderall for the first 2-3 months, I felt like anything was possible and I had no limit to my potential)

-Decreased food intake (My appetite has returned to normal after feeling like I was anorexic for a couple of months)

In short, the Adderall is only working for improved focus now.

Is the decreased effectiveness of Adderall normal? Have I built up a tolerance?

Should I ask my pdoc about raising my dose of Adderall?

Are there any other medications out there that would help (already tried Wellbutrin and it didn't do anything)?

Comments? Suggestions?

P.S. - Please note I take a medication vacation from the Adderall 2 days per week.