Hey Kevin,
I'm curious as to what your prep was before you took the 460. What materials have you been using? What was the Quant and Verbal breakdown on your first prep test? And more importantly, what company's practice test did you use? A 460 on a private company's CAT does NOT necessarily translate to a 460 on the actual GMAT.
To answer your question, 90 points in 5 months is EXTREMELY do-able, especially since you'll have more time starting April 22nd.
What you need now is a consistent study plan, emphasizing high-quality material from GMAC (the GMATPreps, the OG, etc.) and targeted books to help you master the content. If you don't already have them, I'd HIGHLY recommend buying the MGMAT SC book and Powerscore's CR book.
Here's the list of concepts tested on the GMAT. I'd start by choosing 2 Verbal and 2 Quant concepts each week and aim to become an expert in those specific areas, reading up on content, watching videos, doing practice questions for that concept, etc.
Since you have 5 months, definitely don't do everything all at once! Slow and steady wins the race.
QUANTITATIVE
"¢ Absolute Value
"¢ Angles
"¢ Area
"¢ Averages
"¢ Circles
"¢ Coordinate Geometry
"¢ Data Interpretation
"¢ Decimals
"¢ Distance problem
"¢ Estimation
"¢ Evaluating expressions
"¢ Exponents and Roots
"¢ Factors, Divisibility, Primes
"¢ Fractions
"¢ Functions
"¢ Inequalities
"¢ Inscribed Figures
"¢ Interest
"¢ Intersecting lines and angles
"¢ Linear Equations
"¢ Lines
"¢ Mean, Median, Mode
"¢ Mixtures
"¢ Number Properties
"¢ Parallel Lines
"¢ Percents
"¢ Perimeter
"¢ Permutations and Combinations
"¢ Probability
"¢ Profit
"¢ Quadratic Equations
"¢ Quadrilaterals
"¢ Rates and Work
"¢ Ratios and Proportions
"¢ Sequences
"¢ Sets
"¢ Standard Deviation
"¢ System of Linear Equations
"¢ Triangles
"¢ Volume
"¢ Word Problems
VERBAL
"¢ CR: Bolded Statement
"¢ CR: Assumption
"¢ CR: Complete the Passage
"¢ CR: Argument Evaluation
"¢ CR: Flaw
"¢ CR: Numbers and Percentages
"¢ CR: Must Be True
"¢ CR: Cause and Effect
"¢ CR: Method of Reasoning
"¢ CR: Inference
"¢ CR: Resolve the Paradox
"¢ CR: Strengthen
"¢ CR: Weaken
"¢ RC: Application
"¢ RC: Inference
"¢ RC: Function
"¢ RC: Main Idea
"¢ RC: Tone
"¢ RC: Detail
"¢ RC: Vocab in Context
"¢ SC: Subject-Verb Agreement
"¢ SC: Comparisons
"¢ SC: Run-on Sentences
"¢ SC: Meaning
"¢ SC: Idioms
"¢ SC: Modification
"¢ SC: Noun-Verb agreement
"¢ SC: Diction (Superative/Comparative, Countable/Uncountable, etc.)
"¢ SC: Parallelism
"¢ SC: Passive Voice
"¢ SC: Pronouns
"¢ SC: Punctuation
"¢ SC: Sentence Fragment
"¢ SC: Verb Tense
"¢ SC: Wordiness/Redundancy
Hope this helps!