150 mg Effexor XR is still a low dose (in my non-professional opinion).
I am on 450 mg Effexor XR.
Have you considered taking the Effexor XR at different times in the day? For example, I take 300 mg of it in the morning, and 150 mg of it in the early afternoon. This ensures that I am depression-free all day long.
Also you could consider increasing the dose. Effexor XR has honestly been one of the best drugs I've taken for my depression. It has helped a lot. If I remember right, and this isn't medical advice, but the max dosage of Effexor XR is around 375 mg for people with severe depression.
I guess if you're totally finished with the Effexor XR, you could try a different drug, but usually Effexor XR is considered to be one of the more powerful antidepressants. Effexor is an SNRI which means it works on serotonin and norepinephrine, two distinct neurotransmitter systems. I guess that means (in my non-technical opinion) that it helps more. But maybe try increasing the dose or splitting it into different dosing schedules.
Wishing you well.