Is there anyway to find out if I have some sort of spyware or tracking software on my phone?

Help!

Is there a way to find out if someone has downloaded some sort of spyware or tracking software on my phone that would possibly be giving them access to my location?

The person I am concerned with doing this used to have access to my iCloud & my phone was logged into/connected their iTunes. We also used to be on the same account.

Is there a way he could have downloaded some spyware program on my device through one of those means? And how would I go about finding it? Is there a file to be looking for?

I did some research, and these problems (with my phone) lined up with spyware being downloaded on device.

-Battery dies quickly (my phone lasts a few hours at most before needing to be charged. It dies even when not in use)

-Phone randomly lights up when not being used

--productivity & web surfing has gotten very slow.

any advice? I appreciate the help!

Thank You!