Well, procrastination I have found often comes from a fear of failure or being found out that I was not as good as I thought I was expected to be . . . . even short assignments of little if any consequence would take hours upon hours of staring at blank sheets of paper . . .but, I got sick of repeating the cycle just as you are but only you can take action to change . . . .
So, depending on what type of assignment it is, do a check list. Small chunks . . . even 1 minute. . . and put an estimate on that activity and do not go beyond it. If, for example, you say 5 minutes and you have not done anything . . .beep, go on to the next chunk, and return.
Then, do a chunk at a time . . . of course, you actually have to do it . . .
The other issue may be that you like the thrill of doing something at the last minute under pressure . . . a shot of adrenaline and a superior sense of achievement . . .yep, this might work because you are intelligent and great at BS, but in the real world, if you are doing a piece of a project and you are working with other people, they will stomp all over you :)
Look at it this way . . .the sooner you get the assignment done, the more you can reach out to someone else . . . . I am sure that intelligent people are in great demand at homework clubs for younger students who are having problems . . . so, do what you need to do, don't fear getting it done, and take that adrenaline rush and put it to go use . . .yes, it is harder to do than to say, but BS yourself into doing it . . . and let us know how you are doing . .. take care, kc
p.s. I was also a procrastinator and I turned out to be a faculty member .. . .like I say, use that adrenaline to good use