For one that has been playing for two years - and having trouble memorizing - by memorizing the score in your head first - I don't think is the right approach. By playing it, one also reinforces musical memory. So, it would be easiest to memorize this piece in sections - by playing it.
Do you have the first line one memorized yet?
If not, play the first line over and over until you have memorized it. If there are certain spots in the first line where the memory is failing, practice just those bits, maybe a measure long.
After the first line is memorized , go on to the next line, which is mostly the same, except for the last 2 bars.
Then, after you have the first 2 lines, memorize the 3rd line - following the same steps for memorizing as mentioned for line one. (Play several times, notice certain bits which are not catching, and practice just those bars.)
After memorizing line 3, try playing the first 3 lines - from memory. If certain bits aren't catching, practice just those bits.
Apply the same logic for lines 4 and 5. (of course, the last 2 bars of line 4 and line 5 is the same passage as on line 2.
Topic: Strategies for memorizing sheet music