Help for care plan

I am a nursing student, and it is the first time to write a care plan.

And I stuck at the first elements-nursing diagnosis

Case scenario

M,55,severe chest pain due to MI. history of HT.

BP:105/79 HR 110/min , Tem 38.2 Spo2 93

RR 28 , 80kg ,1.6m

c/x chest pain 8/10, radiation to shoulder, profuse sweating and cool in extremities.

c/x running nose,coughs and fever 2 days before diagnosed with URTI.

He was coughing and sneezing and refused to wear mask.Did not know the importance of wearing surgical mask and the proper way to do it. He showed canxious.

I need to identify and prioritize the top 3 problems

I think it is:

1.Decreased cardiac output r/t altered HR AEB 110/min

2.Ineffective breathing pattern r/t obesity AEB 28/min

3.Acute pain r/t ischemia of myocardium AEB 8/10

there are the short form, just for explaining the meaning

but I am not sure the related factors is that right and wrong, and I am not sure about the priority, or are there other diagnosis to replace these top 3.

Please help me, I will finish the intervention and evaluation by myself

thank you