Sergeant Politeness
Where'd That 6th Toe Come From?

To begin, I am not sure if I posted this thread in the right place. If not, feel free to remove it (not that I have much choice on this matter anyway
).
Lately, I've been trying to start roleplaying in games. I use to try making perfect games (doing all quests, finding all items...that kind of thing) but I realised how stupid it was lately and want to roleplay my character, which seems nice.
Problem is, I'm not used to this playstyle and I'm not sure how people do it. I have no problem creating a background for my character, but I can't adapt it to quests. I feel like there is plenty of quests that my character should not be doing but I also feel like I'm missing a big part of the game and XP and I usually end up trying to make excuse for my character to do them.
When I've played a lot of hours, I realize my roleplay is kinda f***ed and I loose motivation. My question is: how do you do it? Do you sacrifice most of the quests/XP to adapt it to your characters? How do you do the main quest and secondary ones in a credible manner? At which level do you finish the game usually while roleplaying in a way that lets you do some quests (I know that some roleplaying involves doing your own thing and not caring about quests)?
I can somehow roleplay a nice guy but roleplaying an ''evil'' character is hard for me. I want to do a character that has some reasons for doing the things he does others than "I'm an asshole", so I'll try to find interesting reasons to do the evil option of the quest. I can create an interesting background but I feel like that character would not do any quests that do not benefit him, which is a LOT.
Not sure if my text is understandable (english isn't my native language) but thanks for any future answers!

Lately, I've been trying to start roleplaying in games. I use to try making perfect games (doing all quests, finding all items...that kind of thing) but I realised how stupid it was lately and want to roleplay my character, which seems nice.
Problem is, I'm not used to this playstyle and I'm not sure how people do it. I have no problem creating a background for my character, but I can't adapt it to quests. I feel like there is plenty of quests that my character should not be doing but I also feel like I'm missing a big part of the game and XP and I usually end up trying to make excuse for my character to do them.
When I've played a lot of hours, I realize my roleplay is kinda f***ed and I loose motivation. My question is: how do you do it? Do you sacrifice most of the quests/XP to adapt it to your characters? How do you do the main quest and secondary ones in a credible manner? At which level do you finish the game usually while roleplaying in a way that lets you do some quests (I know that some roleplaying involves doing your own thing and not caring about quests)?
I can somehow roleplay a nice guy but roleplaying an ''evil'' character is hard for me. I want to do a character that has some reasons for doing the things he does others than "I'm an asshole", so I'll try to find interesting reasons to do the evil option of the quest. I can create an interesting background but I feel like that character would not do any quests that do not benefit him, which is a LOT.
Not sure if my text is understandable (english isn't my native language) but thanks for any future answers!