Let me first say it is a very good question and a wonderful desire to seek God's forgiveness and walk in His divine health.  Praise the Lord for His provision.

Anything we receive from God is done so by faith, believing His Word, or promises.  Healing cannot be earned nor can anything else we seek from our heavenly Father.  It is by faith through His wonderful grace.

I tell you, you can pray for anything, and if you believe that you’ve received it, it will be yours. Mark 11.24 NLT

Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abraham's offspring—not only to those who are of the law but also to those who are of the faith of Abraham. He is the father of us all. Romans 4.16 NIV

It seems through your question that you are in need of some physical healing.  You mentioned you want to receive God's forgiveness so you could receive His healing.

When you were saved God forgave you, or in other words, you received His forgiveness.  So you are now forgiven.  James tells us not to waver in our faith or we will be like the waves of the sea tossed to and fro emotionally.  Again in Mark when you prayed and asked His forgiveness then you must believe you received it at that time and not waver from it.

Therefore if you are forgiven, you are forgiven, rejoice in that! 

Yes, forgiveness from sin and healing are referenced many times in the Bible.  What this tells us is that if you have faith to receive forgiveness, then that same faith will also bring healing if you will exercise your faith for it without wavering.

Surely He has borne our griefs (sicknesses, weaknesses, and distresses) and carried our sorrows and pains [of punishment], yet we [ignorantly] considered Him stricken, smitten, and afflicted by God [as if with leprosy].  But He was wounded for our transgressions, He was bruised for our guilt and iniquities; the chastisement [needful to obtain] peace and well-being for us was upon Him, and with the stripes [that wounded] Him we are healed and made whole.  Isaiah 53.4-5 Amp

Bless the LORD, O my soul, and forget not all his benefits:  Who forgiveth all thine iniquities; who healeth all thy diseases; Psalm 103.2-3

Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.  1 Peter 2.24

Forgiveness of sins and healing are directly related therefore received the same way, as the free gift of God, by grace through faith.

For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Eph 2.8

I would also like to say this before I finish Esther.  There is the possibility of harboring bitterness, resentment and unforgiveness in your own heart against someone and that could prevent your healing.

Looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled;  He 12.15

A calm and undisturbed mind and heart are the life and health of the body, but envy, jealousy, and wrath are like rottenness of the bones. Pr 14.30 AMP

SO BE done with every trace of wickedness (depravity, malignity) and all deceit and insincerity (pretense, hypocrisy) and grudges (envy, jealousy) and slander and evil speaking of every kind.  Like newborn babies you should crave (thirst for, earnestly desire) the pure (unadulterated) spiritual milk, that by it you may be nurtured and grow unto [completed] salvation,  1 Peter 2.1-2 AMP

For if you forgive people their trespasses [their reckless and willful sins, leaving them, letting them go, and, giving up resentment], your heavenly Father will also forgive you.  But if you do not forgive others their trespasses [their reckless and willful sins, leaving them, letting them go, and giving up resentment], neither will your Father forgive you your trespasses.  Matt 6.14-15 AMP

So again Esther, it is all by faith, not feelings nor emotions.  Just by a simple act of your will, decide;

1. to receive God's forgiveness for all your sins,

2. to receive His healing at the same time,

3. to forgive ALL others who may have hurt you in the past or hurt  you in the future

4. Receive His promises in complete confidence and faith.

For no matter how many promises God has made, they are "Yes" in Christ. And so through him the "Amen" is spoken by us to the glory of God.  2 Cor 1.20

Let me know if you have other questions Esther.  We love and appreciate you.

 PS Pray this in faith:  Dear Heavenly Father, Please forgive me of all me sins.  I ask your forgiveness and I now receive your grace and forgiveness.  I also ask that you touch my body and heal all that ails me.  I receive it by faith Father, just like my salvation, I now receive my health.  I choose right now dear Father, to forgive all those who have harmed me in the past, all my relatives and friends, I forgive them all.  I refuse to hold bitterness or resentment against anyone any longer Lord, I give them to you.  Thank you heavenly Father, I believe I receive, and I thank you!  In Jesus name I pray. Amen