Momee, I had been on Effexor for around a decade, starting low and for the last five years of it at 150. Then I hit a weird patch a few years ago where something was not right, it seemed to have lost its benefits. I had read about the "poop out" factor after that long a time, and decided to wean off it, influenced by a doctor who thought it was a bad idea to be on Effexor that long. After getting it out of my system and then spending several months trying to find something else when it was clear I needed something, I found a psychiatrist whose opinion was that rather than dropping it when the 150 stopped being effective he would have advised me to increase the dose. So he got me back on it and gradually went up until in Sept reached his idea of a proper dose, which was 300. I was I wouldn't say filled with doubt, but I didn't want to be on such a high dose yet had to admit that the symptoms, which had become unbearable, were not going to go away by themselves.
Weeks went by and I was still very divided, because I needed this to work, was afraid it wasn't doing enough and still felt unsure about being on twice what I used to take. I wasn't feeling better enough. But I committed to this Dr.'s plan because going by my own instincts hadn't worked several times in a row.
What I'm getting at is that it wasn't until 3 full months after starting 300 that I could tell it was worth it. I think both being on Effexor for so long and then weaning from it and going back on made the timetable much longer than I was counting on. It makes a lot of sense to me that 225 may be right for you at this point, given what you've said. I was also hung up on not going beyond a certain number that represented a pretty big dose to me at the time. And it follows that after lowering it to 75 for six weeks 150 hasn't fallen back in place the way you expected. It might after a while longer, or it might be that he's right, that 150 isn't the right amount at this time.
My own personal advice would be to not be too hesitant about a new higher dose if your Dr. feels it will be a good move. You can always back it off if it effects you adversely. I would say give his strategy a try and give it as much time as he feels is needed.
Good luck with this . : )