Hurt my knee playing soccer hitting another knee head on 5 years ago now i can't do pshyical activities without it giving out with mild pain to follow?

Knee instability: There are many ligaments and tendons which contribute to knee strength. If one of these is injured, it may produce instability (giving out). The injury you describe five years ago (direct blow to the front of the knee) could have injured your knee cartilage, or your anterior cruciate ligament (ACL). Both of these could cause your pain. Seek a sports medicine doctor. MRI would be helpful.