You've solved less than 20 problems in any rating range and in total less than 200 problems. What would you expect?

Source

try to take part in virtual contests and after the contest upsolve one or two problems (see the tutorial and if there is something new for you just google it and try to understand it well)

Solve more problems, take part in virtual contests, probably read some books about algorithms and data structures. The Competitive Programming books by Steven Halim are quite awesome.

I have heard great programmer on you tube say that progress is about the growth and not the rate of growth. I see that you have become pupil from newbie in around 4 — 6 months and I'll say that it is growth.

Apart from that keep reading books, blogs and solving questions above your level but not too above as that might discourage you. Also keep seeing videos and screen cast of good programmers on you tube and see how they are approaching a question. It'll surely help you.

In contests you have difficulties to solve 1200 and up. It seems that you practice with 1500 and up. Solve all (aprox 100) problems of diff 1100-1200 tagged as math. I bet afterwards there will be noticible increase.

I had similar problem and I had the similar graph. I practiced problems with rating greater than 1500 and as said in the earlier comments solve atleast 200 problems in total. Solve C and D problems of Div 3. That was what I did and suggest you to do