Idiom for putting in too much effort

Question

I‘m looking for an idiom which describes that I put too much engagement/pressure in a thing ( a relationship for example) which eventually blew it.

Answer 1

One fairly common expression is trying too hard.

For example usages, it's not too hard to find advice columns entitled something like:

8 Signs You're Trying Too Hard To Make A Relationship Work

10 Signs You’re Trying Too Hard and Turning Him Off

13 Signs You Are Trying Too Hard In A Relationship

Answer 2

To overdo it:

To do so much of an activity that it becomes harmful, detrimental, unenjoyable, or undesirable. (the Free Dictionary)

Examples:

1. I know you're keen to get back into the gym, but don't overdo it or you'll end up hurting yourself.
2. Don't overdo it with loving affection.
3. Don't overdo it, or the search engines might mark down your results.

Answer 3

You can use zealous:

(adj) filled with or inspired by intense enthusiasm or zeal; ardent; fervent

or in your example, overzealous:

(adj) excessively enthusiastic

Answer 4

too much of a good thing TFD idiom

An excessive, unhelpful, or harmful amount of something that is otherwise enjoyable or beneficial.

As in:

I usually take short vacations as I can't stand too much of a good thing.

and

Again a relationship failed. I guess i do not do well with too much of a good thing!