how to deal with a cancerian man?

how to assure him, make him less possessive and less controlling?

Tell him how you truly feel. Listen with out biases. Find a solution that works for both of you

In what ways do you think he's possessive and controlling,

Make him food. Good sex. Loyalty and hustle hard homie.

My ex who I was with for 5 years is a Cancer and the above is true... Food is very important, as is sex lol. I found that being a Cancer they are- in my opinion- the one sign (along with Aries) that are least likely to change in terms of their character. The possessiveness and controlling ways are unlikely to change and there's not much you can do about it. You can reassure him as much as you'd like but don't expect it to change much... Sorry!