Brief Answer:
Pea size lump may be due to
enlarged lymph node.
Detailed Answer:
Hello XXXXXXX
Pea size lymph node behind your ear may be due to enlarged lymph node.It is the site of draining lymph nodes from head and neck.Usually it is due to benign reasons like scalp infection (due to dandruff,louse etc),infection in external ear etc.
In most of the cases it doesn't require any treatment and it will resolve after some time.However other skin lesions like lipoma,
neurofibroma etc need to be ruled out.
It is important to know about brain lesions.If possible please upload MRI report/images so that i can interpret better.
For dizziness,you need proper clinical history and examination.Dizziness can be due to many reasons like
hypertension,
hypoglycemia,migraine,stress etc.
You need routine blood examination like routine hemogram,RBS,LFT,RFT,
Lipid profile,Thyroid profile.Further investigations can be done if needed.
Proper treatment depend upon clinical examination and investigation reports.
Get well soon.
Hope i have answered your query.
Further queries are most welcome.
Take Care
Dr.Indu XXXXXXX