Problem with seo

Hello experts,
I need your suggestion,
One of my site is Web design and development Forum. last month i bought 3000 profile backlink from monsterbacklink.
After the blast my site goes at second page at" web development forum" keyword at google. after that i tried to build some edu backlink manually and bookmark backlink at senukex. Every day i was noticing that my site loosing rank. today i noticed that my site goes 1000+ rank for the keyword. Whats the problem with my site?
Now what i have to do? need urgent solution from experts.