How to keep the tempo for songs with a buncha chunks

Kinda weird question, I don't have a metronome I use my foot to keep the tempo, I find that it's incredibly difficult to play and sing songs that either have a faster beat or a buncha chunks, normal reggae songs. I don't know what to count the chunks as. I mean I can play and sing "Wake up my darling" by Pau hana just fine, but when I go to surf no matter how much I practice it I can have it dead on I start trying to sing everything goes outta whack. Lol is it really just a matter of practice or does anyone have any tips?

The foot thing is a start, but my main tip... Buy a metronome.

IMHO there is no good reason for a musician - beginner or advanced - not to own a metronome, and many reasons why they should.

If you really can't get a metronome, then play along with CDs or MP3s. Something that gives you a reference point.

And don't listen to smug smart @sses who say "Oh, I don't need a metronome". Chances are that their rhythm is not as solid as they'd like to think. Heck, even drummers occasional employ a click track to keep them regular.

Once you have a metronome use it for at least some of every practice session. Even when you have a metronome there is a bit of a learning curve. You may find yourself struggling at first to avoid rushing or dragging the beat. It does indeed come with practice.