A lot of "should"s are leaning on my back. A lot of "should"s are leaning on my back.

A lot of "shoulds" are leaning onagainst my back. A lot of "shoulds" are leaning against my back.

Although not really grammatically correct in majority of sentences, Americans add 's' to things like: shoulds, coulds, buts, etc. when talking about a lot of those things as a noun.

A lot of "shoulds" are leanweighing on my back(mind | head | shoulders). A lot of "shoulds" are weighing on my (mind | head | shoulders).

And I should also finish reading some books. And I should also finish reading some books.

Recently, I have been slacking recently. I have been slacking recently.

Recently, I have been slacking. Recently, I have been slacking.

Or you could say 'slacking off.'

I understand it's time to move my lazy butt and complete all these stufftasks but I can't because I'm way too lazy. I understand it's time to move my lazy butt and complete all these tasks but I can't because I'm way too lazy.

I understand it's time to move my lazy butt and complete all theseis stuff but I can't because I'm way too lazy. I understand it's time to move my lazy butt and complete all this stuff but I can't because I'm way too lazy.

残念！