Declensions? Confused with endings

I love a Serbian.

Я люблю Сербка. Nominative

I love the daughter of a Serbian.

Я люблю дочи Сербки. Genitive

I am offering my love to a Serbian.

Я предлагал свю любове за сербке. Dative

Do not lose patience. It is becoming clear in my head.

I love a Serbian.
Я люблю Сербка. (Nominative) === Я люблю сербку
(I think it's not nominative, it's accusative)

I love the daughter of a Serbian.
Я люблю дочи Сербки. (Genitive) === Я люблю дочь сербки.

I am offering my love to a Serbian.
Я предлагал свю любове за сербке. (Dative) === Я предлагаю (present tense) свою любовь сербке.

I don't understand why you don't buy yourself a grammar book. Your current approach to learning Russian will never get you there.

My dearly beloved grammar book:
RUSSIAN: STAGE ONE Revised Edition /Excercise/Reference Book

By BITEKHTINA, DAVIDSON, DOROFEYEVA, FEDYANINA

With respect to Russian Grammar Books in the Library? They were the only ones stolen. Other language grammar books still reside in their respective shelves. I would like to think that it was an accident. But they were deliberately stolen.

Can anyone suggest a good grammar book which I can buy at amazon.com?

I just bought "A Comprehensive Russian Grammar" by Terence Wade. It hasn't arrived yet, but I have gotten it as a pdf-file on the computer, and it is really neat. Tons of information, easy to use and a nice layout. It is more of a reference grammar though, but you may combine it with "A Russian Grammar Workbook" by the same author, which you can use for drills and exercises.

If you are looking for something with accompanying audio, you should consider "Teach Yourself Russian" by Daphne West or "Teach Yourself Russian Conversation" by Rachel Farmer. Both are very easy to follow and have a focus on everyday topics and conversation, but are of course less heavy on grammar.

Other grammars you could consider looking into are "A Reference Grammar of Russian" by Alan Timberlake, "Basic Russian: A Grammar and Workbook" by John Murray and Sarah Smyth, "Russian: A Self-Teaching Guide" by Kathryn Szczepanska, "Modern Russian Grammar: A Practical Guide" by John Dunn and Shamil Khairov and "Schaum's Outline of Russian Grammar" by James Levine. Only a handful of the many existing grammars on the Russian language.