tomato plants are getting out of control

[McCloudsextoy]

am i supposed to cut the at the top as they are very tall?

Yes you are. I have three plants in a grow bag and when there were 5 lots of flowers on each plant I cut the tops off, also pinch out the shoots which appear in the "armpits" of the plants. That is what I was told to do when I grew my first plant last year and it worked very well - had lots of lovely toms.

oh dear, it makes sense!

even though you cut the tops off they will try to keep growing and take over your garden - you will need to 'prune' off wayward bits regularly until the fruit ripen.