Go wypokie api not working v2

package main

import (
    "crypto/md5"
    "encoding/hex"
    "encoding/json"
    "fmt"
    "io"
    "io/ioutil"
    "log"
    "os"

    "net/http"
    "net/url"
    "strconv"
    "strings"
)

const (
    contentType       = "Content-Type"
    mediaTypeFormType = "application/x-www-form-urlencoded"
    apiSignHeader     = "apisign"
    accountKeyHeader  = "accountkey"
    login             = "login"
)

type WykopHandler struct {
    appKey        string
    authResponse  AuthenticationResponse
    connectionKey string
    secret        string
    login         string
}

type AuthenticationResponse struct {
    Login        string
    Email        string
    ViolationUrl string `json:"violation_url"`
    Userkey      string
}

var wh WykopHandler

func main() {
    wh := WykopHandler{
        appKey:        "APPKEY",
        authResponse:  AuthenticationResponse{},
        connectionKey: "CONNECTIONKEY",
        secret:        "SECRET",
        login:         "asdasdce2w",
    }

    wypok := wh.LoginToWypok()
    fmt.Print(wypok)
}

type WykopError struct {
    ErrorObject WykopErrorMessage `json:"error"`
}

type WykopErrorMessage struct {
    Code    int
    Message string
}

func (wh *WykopHandler) LoginToWypok() *WykopError {

    responseBody := wh.sendPostRequestForBody(getLoginUrl(wh))
    wh.authResponse = AuthenticationResponse{}

    return wh.getObjectFromJson(responseBody, &wh.authResponse)
}

func (wh *WykopHandler) sendPostRequestForBody(address string) string {
    apiHashedSignHeader := wh.hashRequest(address)

    data := url.Values{}
    data.Set(login, wh.login)
    data.Set(accountKeyHeader, wh.connectionKey)

    client := &http.Client{}
    r, _ := http.NewRequest("POST", address, strings.NewReader(data.Encode())) // URL-encoded payload
    r.Header.Add("Content-Type", "application/x-www-form-urlencoded")
    r.Header.Add("Content-Length", strconv.Itoa(len(data.Encode())))
    r.Header.Add("Host", "a2.wykop.pl")
    r.Header.Add("User-Agent", "PostmanRuntime/7.24.1")
    r.Header.Add("Accept-Encoding", "gzip, deflate, br")
    r.Header.Add("Accept", "*/*")
    r.Header.Add("Accept-Encoding", "gzip, deflate, br")
    r.Header.Add("Connection", "keep-alive")
    r.Header.Add(apiSignHeader, apiHashedSignHeader)

    fmt.Println("response:")
    fmt.Println(r)
    resp, _ := client.Do(r)

    fmt.Println(resp.Status)
    io.Copy(os.Stdout, resp.Body)

    if resp.StatusCode == http.StatusOK {
        fmt.Print("Status ok!")
        bodyBytes, err := ioutil.ReadAll(resp.Body)
        if err != nil {
            log.Fatal(err)
        }
        return string(bodyBytes)
    }

    return "???"
}

func (wh *WykopHandler) sendRequestAndReturnStruct(urlAddress string, target interface{}) (wypokError *WykopError) {
    responseBody := wh.sendPostRequestForBody(urlAddress)
    wypokError = wh.getObjectFromJson(responseBody, &target)
    return
}

func (wh *WykopHandler) getObjectFromJson(bodyResponse string, target interface{}) (wypokError *WykopError) {
    b := []byte(bodyResponse)
    if err := json.Unmarshal(b, &wypokError); err != nil {
        // failed to unmarshall error, this is kinda ok, means that API worked
    }

    if wypokError != nil && wypokError.ErrorObject.Message != "" {
        return wypokError
    }

    // if wypokError.ErrorObject.Message != "" {
    //  wypokError = new(WykopError)
    //  wypokError.ErrorObject.Message = "Coś poszło nie tak, wykop api nie zwróciło ani błędu ani obiektu"
    //  wypokError.ErrorObject.Code = -1
    //  return wypokError
    // }

    if targetError := json.Unmarshal(b, target); targetError != nil {
        // this might happen when wypok is being ddosed/updated or Kiner is parting hard in the server room
        // this might happen when a.wykop.pl returned html, or empty response, shit happens.
        wypokError = new(WykopError)
        wypokError.ErrorObject.Message = "Coś poszło nie tak, wykop api nie zwróciło ani błędu ani obiektu"
        wypokError.ErrorObject.Code = -1
        return wypokError
    }
    return nil
}

func (wh *WykopHandler) hashRequest(address string) string {
    toHash := fmt.Sprintf("%s%s%s,%s", wh.secret, address, wh.login, wh.connectionKey)
    fmt.Println("apisign:\n" + toHash)
    mString := []byte(toHash)
    hash := md5.Sum([]byte(mString))
    fmt.Println("hashed apisign:")
    fmt.Println(hex.EncodeToString(hash[:]))
    return hex.EncodeToString(hash[:])
}

func (wh *WykopHandler) SetAppKey(appKey string) {
    wh.appKey = appKey
}

func (wh *WykopHandler) SetSecret(secret string) {
    wh.secret = secret
}

func (wh *WykopHandler) SetConnectionKey(connectionKey string) {
    wh.connectionKey = connectionKey
}

func (wh *WykopHandler) SetLogin(login string) {
    wh.login = login
}

func getLoginUrl(wh *WykopHandler) string {
    return fmt.Sprintf("https://a2.wykop.pl/Login/Index/appkey/%s/", wh.appKey)
}