Back of the Packer

Last night I did weights with my arms at home then went to the gym and did about 20 min of weights for my legs and abs. Then did about 50 lengths in the pool. I tried to time how long it takes me to do 100m because I read an article that said the average time for a tri-swimmer was 1:35-1:50 per 100m and the slow back of the packers are 2:00+ per 100m. Well thats 4 lengths and it took me approx 2:20. That makes me slow. So I spent the whole time trying to get my stroke faster. I guess it just takes practice. Maybe I can look online on how to get faster. But I still have approx 3 months and I have already improved so much so Im not too worried.