Lamotrigine questions?

I know we all have differences in how meds work or don’t work just a question. Is it somewhat normal for 25 mg to help a little for 3 or 4 days then stop working, then 50 mg do the same thing for maybe a little longer, then 150 to work great for maybe 1 1/2 to 2 months and stop working. I just restarted lamotrigine at 25 mg and felt pretty good for two or three days, getting ready to go to 50 mg. What I explained above is what happened last time and after 150 mg quit working I didn’t go up to 200mg because the dose increases were a little rough and I didn’t want to experience feeling good again for a short while then back in hell. My Doctor Who is young and inexperienced told me I should have went up to 200 mg because that’s the therapeutic dose. Should I have? Has anyone had similar experience and then finally got on a dose that continuously worked? I don’t need any horror stories please. Thank you!